15531
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 21504
- Proper Divisor Sum (Aliquot Sum)
- 5973
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9960
- Möbius Function
- -1
- Radical
- 15531
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Graham-Sloane-type lower bound on the size of a ternary (n,3,6) constant-weight code.at n=10A030506
- Numbers whose base-5 representation contains exactly three 1's and three 4's.at n=19A045262
- Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 3 for n > 0.at n=19A101013
- Lucky numbers for which both the sum of the digits and the product of the digits is also a lucky number.at n=34A118559
- a(n) is the reverse concatenation of divisors of n.at n=14A176558
- a(n) = A176558(A175354(n)) = numbers m as reverse concatenations of divisors of numbers from A175354, where A175354 = numbers k such that reverse concatenations of divisors of k are nonprimes.at n=10A176588
- Number of emergent parts in all partitions of n.at n=35A182699
- Number of partitions of n having an ordering of parts in which no parts of equal parity are adjacent and the first and last terms have the same parity.at n=47A239833
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 157", based on the 5-celled von Neumann neighborhood.at n=27A270331
- Lesser of 2 successive sphenic numbers (k, k+4) sandwiching 3 consecutive nonsquarefree numbers.at n=22A363830