1212
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 2856
- Proper Divisor Sum (Aliquot Sum)
- 1644
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 400
- Möbius Function
- 0
- Radical
- 606
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 44
- 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
- a(n) = Sum_{k=0..n} p(k) where p(k) = number of partitions of k (A000041).at n=17A000070
- One half of number of non-self-conjugate partitions; also half of number of asymmetric Ferrers graphs with n nodes.at n=26A000701
- Self numbers divisible by sum of their digits (or, self numbers which are also Harshad numbers).at n=31A003219
- Number of points on surface of cuboctahedron (or icosahedron): a(0) = 1; for n > 0, a(n) = 10n^2 + 2. Also coordination sequence for f.c.c. or A_3 or D_3 lattice.at n=11A005901
- Numbers not of form p + 2^x + 2^y.at n=24A006286
- a(n+1) = a(n)-th composite number, with a(0) = 1.at n=19A006508
- Numbers that are divisible by the product of their digits.at n=43A007602
- Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order.at n=19A007931
- Numbers that contain only 1's, 2's and 3's.at n=49A007932
- Coordination sequence for diamond.at n=22A008253
- Coordination sequence for CaF2(2), Ca position.at n=22A009926
- Coordination sequence for Cr3Si, Si position.at n=9A009927
- Coordination sequence for MgZn2, Position Zn1.at n=9A009937
- a(n) = floor( n*(n-1)*(n-2)/27 ).at n=33A011909
- Number of ferrites M_6Y_n that repeat after 6n+30 layers.at n=18A011962
- a(n) = Sum_{i,j,k in Z and i^2 + j^2 + k^2 <= n} i^2 + j^2 + k^2.at n=11A014203
- Number of partitions of n into its divisors with at least one part of size 1.at n=39A014648
- Number of partitions of n into its nonprime divisors with at least one part of size 1.at n=79A014651
- phi(n) + 8 | sigma(n).at n=43A015799
- Duplicate terms of A007908.at n=1A019524