12881
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14064
- Proper Divisor Sum (Aliquot Sum)
- 1183
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11700
- Möbius Function
- 1
- Radical
- 12881
- 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
- 125
- 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
- Pseudoprimes to base 70.at n=42A020198
- Strong pseudoprimes to base 70.at n=14A020296
- Numbers k such that the continued fraction for sqrt(k) has period 90.at n=26A020429
- Composite numbers whose prime factors contain no digits other than 1 and 7.at n=34A036307
- Gaps of 10 in sequence A038593 (upper terms).at n=9A038660
- Denominators of continued fraction convergents to sqrt(203).at n=4A041377
- Denominators of continued fraction convergents to sqrt(812).at n=4A042567
- Expansion of e.g.f. exp(x/(1-4*x)^(1/2)).at n=5A052142
- Members of A000124 which are multiples of 11.at n=29A083511
- Increasing gaps in A038593 (lower terms).at n=12A093342
- Duplicate of A093342.at n=12A093389
- Numbers n such that p(10n) is prime, where p(n) is the number of partitions of n.at n=20A114170
- a(n) = 8*n^2 + 2*n + 1.at n=40A188135
- Nonprime numbers with all divisors starting and ending with digit 1.at n=15A208261
- Positions of 2 in sequence A217916.at n=20A217918
- a(n) = n + (n-1)*(n-2) + (n-3)*(n-4)*(n-5) + (n-6)*(n-7)*(n-8)*(n-9) + ... + ...*(n-n).at n=17A227363
- Triangle read by rows, T(n,k) = Sum_{j=0..n-k+1} j!*C(n-1,j-1)*T(n-j,k-1) if k != 0 else 1, n>=0, 0<=k<=n.at n=41A256895
- Numbers n whose sum of anti-divisors is a permutation of their digits.at n=28A258786
- a(n) = (2*prime(n)^2 + 1)/3.at n=31A286679
- Composite numbers k with its divisors having the property that the last digit of every divisor is the same as the first digit of the next divisor.at n=17A307858