15309
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 26240
- Proper Divisor Sum (Aliquot Sum)
- 10931
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8748
- Möbius Function
- 0
- Radical
- 21
- Omega Function (Ω)
- 8
- 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
- 84
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Numbers that are the sum of 7 positive 7th powers.at n=35A003374
- Numbers of the form 3^i*7^j with i, j >= 0.at n=28A003594
- a(n) = 7*3^n.at n=7A005032
- Expansion of 1/((1-3*x)*(1-6*x)).at n=5A016137
- Numbers whose prime factors are 3 and 7.at n=15A033850
- a(n) = n*3^n.at n=7A036290
- Triangle whose (i,j)-th entry is binomial(i,j)*3^(i-j)*3^j.at n=29A038221
- Triangle whose (i,j)-th entry is binomial(i,j)*3^(i-j)*3^j.at n=34A038221
- Numbers k that divide 5^k + 4^k.at n=33A045590
- Odd numbers divisible by exactly 8 primes (counted with multiplicity).at n=2A046321
- Numbers k such that 135*2^k-1 is prime.at n=24A050593
- Invert transform applied twice to Pascal's triangle A007318.at n=30A055373
- Invert transform applied twice to Pascal's triangle A007318.at n=33A055373
- Numbers k such that k | 6^k + 5^k + 4^k + 3^k + 2^k + 1^k.at n=45A056745
- Numbers n such that n | 8^n + 7^n + 6^n.at n=36A057233
- Numbers n such that n | 12^n + 11^n + 10^n + 9^n + 8^n + 7^n + 6^n.at n=43A057263
- Numbers n such that n | 12^n + 11^n + 10^n + 9^n + 8^n + 7^n + 6^n + 5^n + 4^n.at n=39A057285
- Numbers k such that k | 11^k + 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k.at n=35A057286
- Numbers n such that n | 10^n + 9^n + 8^n + 7^n + 6^n + 5^n + 4^n + 3^n + 2^n.at n=37A057287
- a(n) = (2n-1) * 3^(2n-1).at n=3A060851