15649
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15650
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15648
- Möbius Function
- -1
- Radical
- 15649
- 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
- 146
- 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
- 1826
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 86 ones.at n=11A031854
- a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A049735.at n=35A049737
- Smallest prime divisor of Kummer numbers ( = primorials - 1), or 1 if no such prime exists.at n=26A057713
- Prime divisors of solutions to 10^n == 1 (mod n).at n=9A066364
- Primes of the form floor((9/8)^k).at n=16A067910
- Numbers m such that the positive values of m - A002110(k) are all primes (k > 0).at n=38A068372
- Primes p such that positive values of p - A002110(k) are all primes for k > 0.at n=19A068374
- Primes of the form n^k + n - 1, where k>0 is minimal.at n=23A076846
- a(n) is the smallest prime of the form n^k + n - 1 with k >= 2.at n=23A078179
- Primes p of the form 2*prime(k) + 3 such that 2*prime(k+1) + 3 is the next prime after p.at n=31A089528
- Last term of prime quadruples.at n=13A090258
- Consider 3 X 3 matrix M = [0 1 0 / 0 0 1 / 5 2 0]; a(n) = the center term in M^n * [1 1 1].at n=12A094248
- Primes that represent some mean of 4 consecutive (2 smaller, itself, 1 larger) primes.at n=37A094932
- Prime numbers p such that pi(p) + 2*p is a square.at n=16A104783
- Number of isomers of polyhex hydrocarbons with C_(2h) symmetry with nineteen hexagons.at n=9A120386
- Prime sums of 6 positive 5th powers.at n=25A123035
- Numbers k such that (14^k - 3^k)/11 is prime.at n=6A128029
- a(n) = 15*n^2 + 9*n + 1.at n=32A134153
- Primes congruent to 40 mod 43.at n=38A142289
- Primes congruent to 45 mod 47.at n=41A142396