15140
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 31836
- Proper Divisor Sum (Aliquot Sum)
- 16696
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6048
- Möbius Function
- 0
- Radical
- 7570
- 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
- 133
- 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
- a(0) = 1, a(n) = 18*n^2 + 2 for n>0.at n=29A010008
- Inverse Euler transform of A000931.at n=47A018243
- Number of partitions of n into parts 3k+1 and 3k+2 with at least one part of each type.at n=46A035620
- Number of configurations of the 5 X 2 variant of Sam Loyd's sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square in one of the corners.at n=46A090036
- Row sums of triangle A091615.at n=11A091621
- a(0) = 1, a(n) = 20*sigma[3](n).at n=9A091983
- a(n) = 8*n^2 + 8*n + 4.at n=43A108099
- Number of irreducible multiple zeta values at weight n.at n=47A113788
- Extrapolation for (n + 1)-st prime made by fitting least-degree polynomial to first n primes.at n=15A140119
- Numbers n with property that (n+1)*prime(n+1)-n*prime(n) is a perfect square s^2.at n=32A181283
- Number of (n+1) X 2 binary arrays with rows and columns in nondecreasing order and with no 2 X 2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=42A184063
- Number of 2 X 2 matrices with all terms in {0,1,...,n} and (sum of terms) = n + 3.at n=40A210375
- Triangle T(n,k) giving the number of terms of A219666 which have n digits (A084558) in their factorial base expansion and whose most significant digit (A099563) in that base is k.at n=42A230420
- Triangle A230420 transposed.at n=38A230421
- Numbers n such that Bernoulli number B_{n} has denominator 330.at n=40A272183
- 1^2 + 3^2, 2^2 + 4^2, 5^2 + 7^2, 6^2 + 8^2, ...at n=43A276764
- Numbers n such that there are precisely 15 groups of orders n and n + 1.at n=5A295995
- Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).at n=31A352331
- Numbers k for which k = phi(k') + phi(k''), where phi is the Euler totient function (A000010), k' the arithmetic derivative of k (A003415) and k'' the second arithmetic derivative of k (A068346).at n=10A352332
- First index k where A368558(k) = 2*n, or 0 if no such index exists.at n=30A388425