15125
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 20748
- Proper Divisor Sum (Aliquot Sum)
- 5623
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11000
- Möbius Function
- 0
- Radical
- 55
- Omega Function (Ω)
- 5
- 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
- 40
- 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
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Associated Mersenne numbers.at n=20A001350
- a(n) = (6*n+1)*(6*n+5).at n=20A001513
- a(n) = (4*n+1)*(4*n+5).at n=30A003185
- Numbers of the form 5^i * 11^j.at n=17A003598
- Alternate Lucas numbers - 2.at n=10A004146
- Expansion of (1+x^2)/(1-2*x+x^3).at n=18A014739
- a(n) = A027052(n, 2n-8).at n=9A027064
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 11 (most significant digit on left).at n=37A029456
- Composite numbers whose prime factors contain no digits other than 1 and 5.at n=21A036305
- Numbers whose prime factors are in {5, 7, 11}.at n=42A036490
- Transformation of A036490: 5^a*7^b*11^c -> 5^a*7^floor((b+2)/2)*11^c.at n=42A036491
- Numbers k that divide 3^k + 2^k.at n=13A045576
- Numbers k that divide 7^k + 3^k.at n=25A045586
- Numbers k that divide 6^k + 4^k.at n=33A045591
- a(1)=9; if n = Product p_i^e_i, n > 1, then a(n) = Product p_{i+2}^{e_i+1}.at n=19A045972
- Shifts left two places under BIN1 transform.at n=20A052341
- Exponential transform of Stirling2 triangle A008277.at n=38A055896
- Numbers k such that k | 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k + 2^k + 1^k.at n=20A056739
- Numbers n such that n | 12^n + 11^n + 10^n + 9^n + 8^n.at n=37A057250
- Number of pairs of partitions of {1,2,...,n} whose meet is the partition {{1}, {2}, ..., {n}}.at n=6A059849