12520
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 28260
- Proper Divisor Sum (Aliquot Sum)
- 15740
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4992
- Möbius Function
- 0
- Radical
- 3130
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 125
- 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
- Number of partitions of at most n into at most 5 parts.at n=37A002622
- McKay-Thompson series of class 6B for Monster.at n=6A007255
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 55.at n=32A031553
- McKay-Thompson series of class 6B for Monster with a(0) = 7.at n=6A045485
- 18-gonal (or octadecagonal) numbers: a(n) = n*(8*n-7).at n=40A051870
- Numbers m such that [A070080(m), A070081(m), A070082(m)] is a right integer triangle.at n=21A070136
- Starting positions of strings of three 3's in the decimal expansion of Pi.at n=7A083610
- Numbers whose set of base 5 digits is {0,4}.at n=34A097251
- n(k) is the minimum n that requires at least k to make 2*Prime[n]+Prime[k] a prime.at n=41A114234
- McKay-Thompson series of class 6B for the Monster group with a(0) = 12.at n=6A121665
- Has two properties: concatenation of its digits is same string as concatenation of digits of its first differences and every number appears exactly one of the sequence or its first differences.at n=43A139310
- Number of (w,x,y) with all terms in {0,...,n} and w<x+y and x<=y.at n=30A212982
- Numbers n such that the difference between the greatest prime divisor of n^3 + 1 and the sum of the other distinct prime divisors is equal to +-1.at n=5A243609
- Numbers k such that Bernoulli number B_{k} has denominator 13530.at n=6A295587
- Triangle read by rows giving the sum of the number of k-matchings of the graphs obtained by deleting one edge and its two vertices from the ladder graph L_n = P_2 X P_n in all possible ways.at n=32A318243
- Numbers k for which A003958(sigma(k)) = 2*A003958(k), where A003958 is multiplicative with a(p^e) = (p-1)^e and sigma is the sum of divisors function.at n=41A351447
- a(1) = 1; a(n) = -Sum_{k=2..n} k^3 * a(floor(n/k)).at n=33A360658