1951
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1952
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 1950
- Möbius Function
- -1
- Radical
- 1951
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 174
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 297
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of partitions of n into relatively prime parts. Also aperiodic partitions.at n=25A000837
- Primes p of the form 3k+1 such that -sqrt(p) < sum_{x=1..p} cos(2*Pi*x^3/p) < sqrt(p).at n=44A000922
- Number of graphical basis partitions of 2n.at n=21A001130
- Artiads: the primes p == 1 (mod 5) for which Fibonacci((p-1)/5) is divisible by p.at n=13A001583
- Cuban primes: primes which are the difference of two consecutive cubes.at n=13A002407
- Hex (or centered hexagonal) numbers: 3*n*(n+1)+1 (crystal ball sequence for hexagonal lattice).at n=25A003215
- Number of free subsets of multiplicative group of GF(5^n).at n=4A007232
- Primes of the form 2*k^2 + 29.at n=29A007641
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=23A007697
- Coordination sequence T1 for Zeolite Code VFI.at n=34A008245
- Crystal ball sequence for planar net 3.6.3.6.at n=29A008580
- Odd primes such that (3p+1)/2 and 3p+4 are also prime.at n=21A014223
- Number of triples of different integers from [ 2,n ] with no global factor.at n=24A015618
- Numbers k such that the continued fraction for sqrt(k) has period 68.at n=1A020407
- Numbers with exactly 9 ones in binary expansion.at n=34A023691
- a(n) = least m such that if r and s in {1/3, 1/6, 1/9,..., 1/3n} satisfy r < s, then r < k/m < s for some integer k.at n=29A024824
- Coordination sequence T1 for Zeolite Code IFR.at n=31A024982
- Coordination sequence T4 for Zeolite Code IFR.at n=31A024985
- a(n) = T(n,n) + T(n,n+1) + ... + T(n,2n), T given by A027113.at n=7A027129
- a(n) = prime(9*n).at n=32A031342