12961
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13972
- Proper Divisor Sum (Aliquot Sum)
- 1011
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11952
- Möbius Function
- 1
- Radical
- 12961
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 169
- 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
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=42A024844
- Numbers k such that k^2 and k^3 have the same set of digits.at n=19A029797
- Numbers k such that 281*2^k + 1 is prime.at n=21A053357
- Third row of Pascal-(1,5,1) array A081580.at n=27A081589
- Shifts 1 place left under the BINOMIAL transform of the self-convolution of this sequence.at n=7A090363
- a(n) = 8*n^2 + 4*n + 1.at n=40A102083
- Column k=2 sequence of array A103728.at n=36A103729
- a(1)=1. For m >= 0 and 1 <= k <= 2^m, a(2^m +k) = a(k) + Sum_{j=1..2^m} a(j).at n=32A139485
- Natural growth of an aliquot sequence driven by a perfect number 2^(p-1)*((2^p) - 1).at n=20A146556
- a(n) = 10*n^2 + 1.at n=36A158187
- a(n) = 324*n + 1.at n=39A158272
- a(n) = 40*n^2 + 1.at n=18A158602
- Positive numbers y such that y^2 is of the form x^2+(x+151)^2 with integer x.at n=9A161483
- a(n) = 10*6^n+1.at n=4A199414
- Beach-Williams Pell numbers of type pq (p,q primes).at n=10A212078
- Positions of incrementally largest terms in the continued fraction of the Glaisher-Kinkelin constant A.at n=8A225752
- Number of nX2 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X3 binary array.at n=4A226846
- Number of nX5 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X6 binary array.at n=1A226849
- T(n,k) is the number of n X k (0,1,2) arrays of permanents of 2 X 2 subblocks of some (n+1) X (k+1) binary array.at n=16A226852
- T(n,k) is the number of n X k (0,1,2) arrays of permanents of 2 X 2 subblocks of some (n+1) X (k+1) binary array.at n=19A226852