1913
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1914
- 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
- 1912
- Möbius Function
- -1
- Radical
- 1913
- 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
- 81
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 293
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Coefficients in expansion of permanent of infinite tridiagonal matrix shown below.at n=51A003113
- Number of partitions of n into parts 5k+1 or 5k+4.at n=56A003114
- From relations between Siegel theta series.at n=18A006476
- Primes with both 10 and -10 as primitive root.at n=55A007349
- Primes p == 1 (mod 8), p = a^2 + 64*b^2 such that y^2 = x^3 + p*x has rank 2.at n=26A007766
- Coordination sequence T2 for Zeolite Code MEP.at n=26A008158
- Coordination sequence T1 for Zeolite Code MER.at n=32A008160
- Coordination sequence T6 for Zeolite Code PAU.at n=32A008224
- Year of birth of n-th President of U.S.A.at n=37A008745
- Year of birth of n-th President of U.S.A.at n=36A008745
- If a, b in sequence, so is ab+5.at n=28A009304
- Coordination sequence T2 for Zeolite Code -CHI.at n=28A009847
- Coordination sequence T4 for Zeolite Code -CLO.at n=38A009853
- Numbers in which every prefix (in base 10) is 1 or a prime.at n=46A012883
- Primes p == 1 mod 8 such that 2 and -2 are both 4th powers (one implies other) mod p.at n=33A014754
- Numbers k such that the continued fraction for sqrt(k) has period 29.at n=4A020368
- Primes that remain prime through 2 iterations of the function f(x) = 2x + 7.at n=28A023244
- Primes that remain prime through 2 iterations of function f(x) = 3x + 10.at n=49A023249
- Numbers k such that the sum of the digits of Fibonacci(k) in base 11 is k.at n=50A025490
- T(2n,n-1), T given by A026692.at n=5A026694