15613
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16828
- Proper Divisor Sum (Aliquot Sum)
- 1215
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14400
- Möbius Function
- 1
- Radical
- 15613
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 177
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- Number of partitions of n into an odd number of parts.at n=39A027193
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 9.at n=26A031422
- Number of cycle types of conjugacy classes of all even permutations of n elements.at n=39A046682
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 17.at n=16A051982
- Stirling transform of Catalan numbers: a(n) = Sum_{k=0..n} Stirling2(n, k)*binomial(2*k, k) / (k+1).at n=7A064856
- Interprimes (A024675) which are of the form s*prime, s=13.at n=9A075288
- Numbers n such that sum of squares of even digits of n equals sum of squares of odd digits of n.at n=21A076164
- "Orderly" Friedman numbers (or "good" or "nice" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order.at n=22A080035
- Composite n such that both n and its reversal in base 10 are squarefree, none of the prime factors of n are palindromes and the prime factors of the reversal of n are the reversals of those of n.at n=4A083526
- Integers n such that by inserting between their digits + or - or * or / or ^ or nothing (i.e., concatenate two digits) you recover n back in a nontrivial way.at n=4A157198
- The number of odd partitions of consecutive odd integers.at n=19A160786
- Number of (n+1) X (2+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0011 or 0111.at n=6A259244
- Number of (n+1)X(7+1) 0..1 arrays with each 2X2 subblock having clockwise pattern 0000 0011 or 0111.at n=1A259249
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with each 2X2 subblock having clockwise pattern 0000 0011 or 0111.at n=29A259250
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with each 2X2 subblock having clockwise pattern 0000 0011 or 0111.at n=34A259250
- Numbers whose Euler totient function is equal to the product of the number of divisors of their k first powers, for some k.at n=33A283759
- Number of integer partitions of n with reverse-alternating sum >= 0.at n=39A344607