17923
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17924
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 17922
- Möbius Function
- -1
- Radical
- 17923
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- no
- Narcissistic Number
- no
- Collatz Steps
- 48
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 2055
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 2x + 5.at n=41A023274
- Numbers k in which the digits of k^2 appear.at n=27A029774
- Primes p such that all digits of p^2 appear in p.at n=1A030083
- Upper twin primes of upper twin prime index.at n=19A088463
- Number of partitions of n having exactly one part that is a multiple of 3.at n=44A116634
- Numbers k such that k and k^2 use only the digits 1, 2, 3, 7 and 9.at n=17A136983
- Primes congruent to 46 mod 59.at n=32A142773
- Primes congruent to 50 mod 61.at n=33A142848
- Binomial transform of [1, 4, 10, 20, 0, 0, 0, ...].at n=18A143131
- Primes remaining primes under map 2<=>9 (interchange of decimal digits 2 and 9).at n=33A198146
- The number of reversible primes (palindromic or emirps) by increasing permissible leading digit and by length.at n=25A220344
- Smallest k<3*2^n such that 3*2^n+k is the smallest of four consecutive primes in arithmetic progression or 0 if no solution.at n=44A230852
- T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=37A239599
- Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=7A239600
- Number of length n+5 0..6 arrays with some three disjoint pairs in each consecutive six terms having the same sum.at n=2A248487
- T(n,k)=Number of length n+5 0..k arrays with some three disjoint pairs in each consecutive six terms having the same sum.at n=30A248489
- Number of length 3+5 0..n arrays with some three disjoint pairs in each consecutive six terms having the same sum.at n=5A248492
- a(n) = 21*n^2 - 33*n + 13.at n=29A289134
- Primes in A374965 sorted into increasing order.at n=36A373804
- Prime numbersat n=2055