17888
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 38808
- Proper Divisor Sum (Aliquot Sum)
- 20920
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8064
- Möbius Function
- 0
- Radical
- 1118
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 92
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Smallest multiple of n whose digits sum to n.at n=32A002998
- Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,3.at n=5A037593
- T(n,n), array T as in A047110.at n=9A047112
- Difference between larger and smaller terms of n-th amicable pair.at n=26A066539
- Smallest proper multiple of n with digit sum n.at n=31A069035
- Numbers n such that sigma(n) + sigma(n+3) = sigma(n+1) + sigma(n+2).at n=3A076666
- Smallest multiple of n with two or more digits, none of them zeros, whose digit sum equals n, or 0 if no such multiple exists.at n=31A077754
- a(1) = a(2) = 1. For n >=3, a(n) = the a(n-2)th integer, among those positive integers which are missing from the first (m-1) terms of the sequence, below a(n-1) if such a positive integer exists. Otherwise, a(n) = the a(n-2)th integer, among those positive integers which are missing from the first (m-1) terms of the sequence, above a(n-1).at n=38A118627
- a(n) is the smallest number which is divisible by n, is not equal to n and its digital sum is also divisible by n.at n=31A163502
- Difference A063990(2n)-A063990(2n-1) between amicable numbers.at n=26A178542
- 1/4 the number of arrangements of n+1 nonzero numbers x(i) in -2..2 with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero.at n=7A189944
- T(n,k)=1/4 the number of arrangements of n+1 nonzero numbers x(i) in -k..k with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero.at n=43A189951
- 1/4 the number of arrangements of 9 nonzero numbers x(i) in -n..n with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero.at n=1A189958
- Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) <= number of parts of p.at n=37A241829
- Least integer m > 0 with pi(m*n) = sigma(m) + sigma(n), where pi(.) and sigma(.) are given by A000720 and A000203 respectively.at n=21A247673
- Number of (n+2)X(n+2) 0..1 arrays with every 2X2 and 3X3 subblock diagonal maximum minus antidiagonal minimum nondecreasing horizontally and vertically.at n=5A253502
- Number of (n+2)X(6+2) 0..1 arrays with every 2X2 and 3X3 subblock diagonal maximum minus antidiagonal minimum nondecreasing horizontally and vertically.at n=5A253508
- a(n) = n*(n^2 + 3*n - 2)/2.at n=32A256857
- Somos's sequence {b(4,n)} defined in comment in A078495: a(0)=a(1)=...=a(10)=1; for n>=11, a(n)=(a(n-1)*a(n-10)+a(n-5)*a(n-6))/a(n-11).at n=27A271949
- Difference between the larger and smaller terms of the n-th amicable pair (x,y) given in A259933.at n=26A275469