15651
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 23712
- Proper Divisor Sum (Aliquot Sum)
- 8061
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9936
- Möbius Function
- 0
- Radical
- 5217
- Omega Function (Ω)
- 4
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 146
- 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
- no
- Odd
- yes
Appears in sequences
- Sums of 3 distinct powers of 5.at n=21A038475
- Palindromic and divisible by 9.at n=28A045644
- Palindromes with successive increasing difference: a(k)-a(k-1) > a(k+1)- a(k).at n=37A071250
- Smallest k>n such that n^3+1 divides k*n^2+1.at n=25A071568
- Numbers n for which there are exactly six k such that n = k + reverse(k).at n=35A072430
- Palindromes in A082939.at n=15A082940
- Diagonal of A083464.at n=24A083465
- a(1) = 7 then the smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=36A083994
- Smallest palindrome such that every partial concatenation is prime.at n=38A089336
- In binary representation: least number, k, which occurs n times in its factorial.at n=23A093826
- Consider all (2n+1)-digit palindromic primes of the form 70...0M0...07 (so that M is a palindrome with <= 2n-1 digits); a(n) = smallest such M.at n=51A100956
- a(n+1) = least palindrome not already used that is either a divisor or multiple of a(n) such that the ratios a(n+1)/a(n) are all distinct.at n=41A111678
- Palindromes equal to the sum of a prime number with its index.at n=29A115888
- a(3n) = floor(43*2^n/28) - 1, a(3n+1) = a(3n) + 3*2^(n-3), a(3n+2) = floor(17*2^n/7 - 6/7) for n>=3.at n=40A123946
- Palindromic mountain numbers.at n=27A173070
- a(n) = Sum_{d|n} d^tau(d).at n=24A174937
- Sum of increasing powers of divisors: a(n) = Sum_{i=1..q} d(i)^i where d(1) < d(2) < ... < d(q) are the divisors of n.at n=24A180851
- Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=11A207165
- Triangle of coefficients of polynomials u(n,x) jointly generated with A210804; see the Formula section.at n=50A210803
- Numbers k such that k!6 + 8 is prime, where k!6 is the sextuple factorial number (A085158 ).at n=18A288152