15725
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
- 21204
- Proper Divisor Sum (Aliquot Sum)
- 5479
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11520
- Möbius Function
- 0
- Radical
- 3145
- 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
- 84
- 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
- Numbers that are the sum of 2 nonzero squares in exactly 6 ways.at n=7A025289
- Numbers that are the sum of 2 nonzero squares in 5 or more ways.at n=11A025296
- Numbers that are the sum of 2 nonzero squares in 6 or more ways.at n=7A025297
- Numbers that are the sum of 2 distinct nonzero squares in exactly 6 ways.at n=7A025307
- Numbers that are the sum of 2 distinct nonzero squares in 5 or more ways.at n=9A025315
- Numbers that are the sum of 2 distinct nonzero squares in 6 or more ways.at n=7A025316
- McKay-Thompson series of class 21D for Monster.at n=24A058566
- Smallest a(n)>2 such that all integers strictly between a(n)-n and a(n) are composite.at n=41A075741
- Smallest multiple of n beginning with the n-th prime.at n=36A078208
- a(n) = floor(6^n/5^n).at n=53A094983
- a(n) is the area of the triangle with sides prime(n), prime(n+2) and prime(n+4), rounded down to the nearest integer.at n=38A096384
- Numbers m that are the hypotenuse of exactly 22 distinct integer-sided right triangles, i.e., m^2 can be written as a sum of two squares in 22 ways.at n=7A097103
- Indices of primes in sequence defined by A(0) = 93, A(n) = 10*A(n-1) - 7 for n > 0.at n=9A101002
- a(n) = n*(n+13)*(n+14)/6.at n=37A111144
- a(n) = a(n - 1) - 2*a(n - 2) + a(n - 3) - 2*a(n - 4) + a(n - 5).at n=39A122582
- Primitive subsequence of A111105.at n=27A137559
- 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, 0, 1), (-1, 1, 1), (1, -1, 0), (1, 0, -1), (1, 0, 1)}.at n=8A149406
- a(n) = n*(n^2+4).at n=25A155965
- First string of 43 consecutive composite numbers.at n=41A177949
- McKay-Thompson series of class 21D for the Monster group with a(0) = 2.at n=24A226015