13251
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20224
- Proper Divisor Sum (Aliquot Sum)
- 6973
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7560
- Möbius Function
- -1
- Radical
- 13251
- Omega Function (Ω)
- 3
- 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
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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 8 positive 7th powers.at n=40A003375
- Numbers k that divide s(k), where s(1)=1, s(j)=21*s(j-1)+j.at n=34A014872
- a(n) = n*(15*n + 1)/2.at n=42A022273
- 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 76.at n=29A031574
- a(0)=2; a(n) is the smallest k > a(n-1) such that the fractional part of k^(1/11) starts with n.at n=37A034076
- Numbers whose base-4 representation contains exactly three 0's and four 3's.at n=7A045080
- Row sums of A075652.at n=20A075650
- Triangle T(n,k) read by rows; given by [0,1,0,1,0,1,0,1,...] DELTA [1,1,1,2,1,3,1,4,1,5,1,6,...], where DELTA is Deléham's operator defined in A084938.at n=42A085838
- Structured triakis tetrahedral numbers (vertex structure 4).at n=20A100175
- Numbers n such that z(n) and z(n+1) are both prime, where z(n) = a^d + b^d + c^d + ..., where a*b*c* ... is the prime factorization of n and d is the largest digit of n.at n=14A109280
- Start with 1 and repeatedly reverse the digits and add 65 to get the next term.at n=28A118163
- Sum of squares of three consecutive primes.at n=17A133529
- G.f.: A(q) = exp( Sum_{n>=1} A162552(n) * 3*A038500(n) * q^n/n ).at n=25A161808
- Smallest number m such that exactly n odd numbers can be seen as proper subsequences of m in decimal representation.at n=25A164766
- Number of 4-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero with no three beads in a row equal.at n=20A208946
- Number of partitions of n such that no part is a sum of two other parts.at n=47A236912
- Numbers m such that there are precisely 7 groups of order m.at n=47A249550
- Number of integer partitions of the n-th even number or the n-th odd number using predecessors of prime numbers.at n=32A280962
- Numbers k such that (56*10^k + 367)/9 is prime.at n=15A294231
- Number of compositions of n with cuts-resistance <= 2.at n=16A330028