13957
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14796
- Proper Divisor Sum (Aliquot Sum)
- 839
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13120
- Möbius Function
- 1
- Radical
- 13957
- 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
- 89
- 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
- Expansion of e.g.f. cosh(log(1+x))/cosh(x).at n=8A009131
- Numbers k such that the continued fraction for sqrt(k) has period 57.at n=24A020396
- Expansion of Product_{k >= 1} 1/(1-x^k)^c(k), where c(1), c(2), ... = 2 3 2 3 2 3 2 3 ....at n=16A029863
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 17.at n=13A051982
- Number of partitions of n in SPM(n): these are the partitions obtained from (n) by iteration of the following transformation: p -> p' if p' is a partition (i.e., decreasing) and p' is obtained from p by removing a unit from the i-th component of p and adding one to the (i+1)-th component, for any i.at n=47A056219
- Rounded total surface area of a regular dodecahedron with edge length n.at n=26A071397
- a(n) = 7^n - 5^n + 3^n + 2^n.at n=5A135164
- Numbers k such that continued fraction of (1 + sqrt(k))/2 has period 17.at n=39A146340
- Semiprimes which are the sum of three distinct positive cubes in two or more distinct ways.at n=14A180089
- Numbers k such that 13*10^k + 1 is prime.at n=15A289051
- Number of sets of exactly eight nonempty words with a total of n letters over n-ary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.at n=3A293970
- Numbers k such that k![4] - 256 is prime, where k![4] = A007662(k) = quadruple factorial.at n=33A329177
- Index where prime(n) appears as a term in A379442.at n=44A379558