13625
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 17160
- Proper Divisor Sum (Aliquot Sum)
- 3535
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10800
- Möbius Function
- 0
- Radical
- 545
- Omega Function (Ω)
- 4
- 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
- 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
- Number of Twopins positions.at n=23A005689
- Numbers k such that 2*6^k - 1 is prime.at n=37A057472
- Expansion of (1-x)/(1-x+2*x^2-x^3).at n=35A078019
- Numbers n that are the hypotenuse of exactly 10 distinct integer-sided right triangles, i.e., n^2 can be written as a sum of two squares in 10 ways.at n=27A097225
- Number of partitions of n such that the set of parts and the set of multiplicities of parts are disjoint.at n=52A114639
- Expansion of 1/(1 + 2*x + 3*x^2 + x^3).at n=23A127896
- a(0)=-1, a(1)=0, a(2)=1, a(n) = a(n-1) - 2*a(n-2) + a(n-3).at n=37A141576
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (-1, 1, 1), (1, -1, -1), (1, 1, 1)}.at n=8A149530
- Totally multiplicative sequence with a(p) = a(p-1) + 8 for prime p.at n=30A166705
- Expansion of x*(1 - x^2)/(1 - x + 7*x^2 + x^3).at n=11A174792
- Partial sums of A033485.at n=36A178855
- Diagonal sums of the triangular matrix A190088.at n=9A190090
- Number of (n+1)X(n+1) 0..2 symmetric matrices containing all values 0..2 with every 2X2 subblock having one or three distinct values, and new values 0..2 introduced in lower triangle row major order.at n=4A210810
- a(n) = 7*n^2 + 2*n - 15.at n=43A239796
- Number of n X 3 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=20A240757
- Number of length 4+2 0..n arrays with some pair in every consecutive three terms totalling exactly n.at n=7A245873
- Expansion of Sum_{i>=1} mu(i)^2*x^i/(1 - x^i) * Product_{j=1..i} 1/(1 - mu(j)^2*x^j), where mu() is the Moebius function (A008683).at n=40A284835
- p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = (1 - S)(1 + S^2).at n=27A291741
- a(n) = A292136(n)^2 + A292137(n)^2.at n=54A292464
- a(n) = Sum_{-n<i<n, -n<j<n, gcd{i,j}=2} (n-|i|)*(n-|j|)/8.at n=28A331773