1257
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1680
- Proper Divisor Sum (Aliquot Sum)
- 423
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 836
- Möbius Function
- 1
- Radical
- 1257
- Omega Function (Ω)
- 2
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 39
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Number of points of norm <= n^2 in square lattice.at n=20A000328
- Number of inequivalent strong starters in cyclic group of order 2n+1.at n=10A006205
- Generalized Fibonacci numbers A_{n,4}.at n=27A006209
- Discriminants of totally real cubic fields.at n=32A006832
- Number of 5th-order maximal independent sets in path graph.at n=40A007380
- a(n+1) = (2n+3)*a(n) - 2n*a(n-1) + 8n, a(0) = 1, a(1) = 3.at n=4A007566
- Coordination sequence T3 for Zeolite Code CAS.at n=22A008065
- Coordination sequence T1 for Zeolite Code LTA and RHO.at n=28A008137
- Table T(n,k), n>=0 and k>=0, read by antidiagonals: the k-th column given by the k-th Narayana polynomial.at n=49A008550
- Expansion of (1+x^9)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=44A008770
- Coordination sequence T4 for Zeolite Code CON.at n=25A009871
- a(n) = n^2 + 3*n - 1.at n=34A014209
- Number of (unordered) triples of integers from [1,n] with no common factors between pairs.at n=28A015617
- Values of n for which exp(Pi*sqrt(n)) is very close to an integer.at n=45A019296
- Number of nonisomorphic cyclic subgroups of alternating group A_n (or number of distinct orders of even permutations of n objects); number of different LCM's of partitions of n which have even number of even parts.at n=54A020902
- Index of 3^n within sequence of numbers of form 2^i*3^j (A003586).at n=39A022330
- Convolution of A023531 and Fibonacci numbers.at n=16A023557
- Convolution of A023531 and (F(2), F(3), F(4), ...).at n=15A023561
- Convolution of A023532 and odd numbers.at n=39A023601
- Discriminants of totally complex quartic fields.at n=51A023682