15572
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 28980
- Proper Divisor Sum (Aliquot Sum)
- 13408
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7296
- Möbius Function
- 0
- Radical
- 7786
- 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
- 102
- 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
- One half of number of non-self-conjugate partitions; also half of number of asymmetric Ferrers graphs with n nodes.at n=39A000701
- Number of Twopins positions.at n=21A005687
- Coordination sequence for MgNi2, Position Ni2.at n=31A009932
- Number of partitions of n into an even number of parts.at n=39A027187
- n*10^7-1, n*10^7-3, n*10^7-7 and n*10^7-9 are all prime.at n=1A064982
- Sum of numbers in n-th upward diagonal of triangle in A079823.at n=46A079824
- Row sums of triangle A137712.at n=20A137713
- Sum of first k numbers in column k of the natural number array A000027; by antidiagonals.at n=23A185787
- Number of (n+1) X (2+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=3A235020
- Number of (n+1) X (4+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=1A235022
- T(n,k) is the number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=11A235026
- T(n,k) is the number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=13A235026
- Number of partitions of 2n+1 of type OO (see Comments).at n=19A236914
- a(n) = Sum_{i=1..n} (-1)^{i+1} prime(i)^2, where prime(k) denotes the k-th prime: alternating sum of the squares of the first n primes.at n=36A240860
- Number of length n 0..2 arrays with new values introduced in order from both ends, and least squares fitting to a straight line with slope zero, with a single point taken as having zero slope.at n=14A245845
- Triangle T(n,k) read by rows: coefficients of polynomials P_n(t) defined in Formula section.at n=22A278457
- Numbers k such that (19*10^k + 413)/9 is prime.at n=19A293684
- a(1)=0; for n>1, a(n) = 4*n^3 - 3*n^2 - 3*n + 4.at n=15A296363
- Number of series-reduced locally disjoint rooted trees with n unlabeled leaves.at n=13A316697
- Number of integer partitions of n with reverse-alternating sum < 0.at n=39A344608