12778
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19170
- Proper Divisor Sum (Aliquot Sum)
- 6392
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6388
- Möbius Function
- 1
- Radical
- 12778
- 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
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 29.at n=34A020368
- a(n) = least 2k such that p is the least prime in a Goldbach partition of 2k, where p = prime(n).at n=23A025017
- Let C(n) = product of composite numbers between the n-th prime and (n+1)-th prime; a(n) = floor(C(n+1)/C(n)).at n=21A073836
- Numbers k such that k!!!! - 1 is prime.at n=25A085147
- Records in A025017.at n=11A133427
- Number of nX4 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 2 neighbors with the same value.at n=11A164756
- Number of 8-step one space leftwards or up, two space rightwards or down asymmetric rook's tours on an n X n board summed over all starting positions.at n=4A187303
- Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=14A192976
- Number of integer partitions whose sum plus co-rank is n, where co-rank is maximum of length and largest part.at n=48A325193
- E.g.f.: exp( exp(x) * (1 + x + x^2 / 2 + x^3 / 6) - 1 ).at n=6A347666
- Partial sums of A365414.at n=47A365444