15450
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
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 38688
- Proper Divisor Sum (Aliquot Sum)
- 23238
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4080
- Möbius Function
- 0
- Radical
- 3090
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 146
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 0, a(1) = 2, a(2) = 1.at n=17A020992
- Number of rooted trees with n nodes and 3 leaves.at n=27A055278
- a(1) = 932; for n > 1, a(n) = a(n-1) + 1 + sum of distinct prime factors of a(n-1) that are < a(n-1).at n=38A105213
- Number of partitions of n-1 boys and one girl with no couple.at n=28A120452
- Numbers k such that if x = Sum_{j|k, j<k} (sigma(j) - j) then k = Sum_{j|x, j<x} (sigma(j) - j).at n=3A238765
- Number of partitions of n having 1 more even part than odd, so that there is an ordering of parts for which the even and odd parts alternate and the first and last terms are even.at n=52A239832
- Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 1.at n=50A240010
- Total binary weight (cf. A000120) of all A005251(n) binary sequences of length n not containing any isolated 1's.at n=14A259966
- Number of bi-unitary abundant numbers < 10^n.at n=4A302994
- Number of chordless cycles in the n-triangular honeycomb bishop graph.at n=7A370228
- Expansion of 1/sqrt(1 - 4*x/(1 - x^3)^2).at n=8A376811
- a(n) is the number of multisets of n positive decimal digits where the sum of the digits equals the product of the prime digits.at n=40A384505
- Intersection of A391845 and A391866.at n=47A392592