15647
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15648
- 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
- 15646
- Möbius Function
- -1
- Radical
- 15647
- 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
- 84
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1825
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=33A023297
- Palindromic primes in base 4.at n=41A029972
- Restricted left truncatable (Henry VIII) primes.at n=8A055521
- Smallest n-digit left truncatable prime of Henry VIII type.at n=2A060825
- Primes p such that (p-1)/2 and (p-3)/4 are also prime.at n=27A066179
- Numbers k such that sigma(k+2) - sigma(k) = prime(k+1) - prime(k).at n=35A067062
- Primes of the form 16*k-1 such that 4*k-1 and 8*k-1 are also primes.at n=15A101793
- a(n) = 4*n^3 - 3*n^2 + 2*n - 1.at n=15A131464
- Prime quadruples: 3rd term.at n=13A136721
- Primes congruent to 38 mod 43.at n=40A142287
- Primes congruent to 16 mod 49.at n=38A142427
- Primes congruent to 12 mod 53.at n=38A142542
- Primes congruent to 12 mod 59.at n=32A142739
- Primes congruent to 31 mod 61.at n=34A142829
- Primes of the form n+(n+3)^3, n>=0.at n=5A162004
- Primes of the form 7*x^2 - 5*y^2, where x and y are successive natural numbers.at n=31A176557
- Primes p of the form 6n-1 such that p-1 is a semiprime and p+2 is prime or prime squared.at n=44A181669
- Gullwing primes: primes in the gullwing sequence A187220.at n=31A187222
- Primes p with p + 2 and prime(p) + 2 both prime.at n=32A236458
- Left-truncatable primes p with property that prepending any single decimal digit to p does not produce a prime.at n=10A240768