15624
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 49920
- Proper Divisor Sum (Aliquot Sum)
- 34296
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4320
- Möbius Function
- 0
- Radical
- 1302
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 4
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
- yes
- Harshad Number
- yes
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Theta series of direct sum of 2 copies of f.c.c. lattice.at n=25A008663
- a(n) = 5^n - 1.at n=6A024049
- Gaps of 7 in sequence A038593 (upper terms).at n=37A038654
- Numbers ending with '4' that are the difference of two positive cubes.at n=33A038859
- Numbers that are repdigits in base 5.at n=24A048330
- Number of factorizations into distinct factors with 3 levels of parentheses indexed by prime signatures. A050349(A025487).at n=38A050350
- Expansion of square of g.f. for A051573.at n=12A051603
- Closed 3-dimensional ball numbers (version 2): a(n)= number of integer points (i,j,k) contained in a closed ball of diameter n, centered at (1/2,0,0).at n=31A053593
- Number of connected 3 X n binary matrices with rightmost column [1,1,1]', divided by 4.at n=5A054418
- Numbers k such that k^4 == 1 (mod 5^5).at n=19A056102
- Array of values of Jordan function J_k(n) read by antidiagonals (version 1).at n=50A059379
- Array of values of Jordan function J_k(n) read by antidiagonals (version 2).at n=49A059380
- Number of conjugacy classes in the group GL_2(K) when K is a finite field with q = p^m for a prime p and m >= 1.at n=41A060615
- Positive numbers which are one less than a perfect square that is also another power.at n=13A062965
- a(n) = n*5^n - 1.at n=4A064751
- Engel expansion of sinh(1/2).at n=31A068379
- a(n) = n^3 - 1.at n=24A068601
- Jordan function J_6(n).at n=4A069091
- "Orderly" Friedman numbers (or "good" or "nice" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order.at n=28A080035
- a(n) = (n-1)^n - 1.at n=6A085606