1015
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1440
- Proper Divisor Sum (Aliquot Sum)
- 425
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 672
- Möbius Function
- -1
- Radical
- 1015
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 36
- 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
- Number of integers <= 2^n of form 4 x^2 + 4 x y + 5 y^2.at n=13A000076
- Square pyramidal numbers: a(n) = 0^2 + 1^2 + 2^2 + ... + n^2 = n*(n+1)*(2*n+1)/6.at n=14A000330
- Numbers k such that phi(k) = phi(k+2).at n=23A001494
- Numbers of the form (p^2 - 1)/120 where p is 1 or prime.at n=31A002381
- Odd squarefree numbers with an odd number of prime factors that have no prime factors greater than 31.at n=42A002556
- Expansion of e.g.f. tan(sinh(x)) (odd powers only).at n=3A003716
- Expansion of (1 + x - x^5) / (1 - x)^3.at n=40A004120
- Primes written in base 6.at n=48A004680
- Number of classifications of n elements.at n=7A005646
- a(n) = binomial(n+3, 3)/4 for odd n, n*(n+2)*(n+4)/24 for even n.at n=27A006918
- Number of partitions of n into parts of sizes {a( )} is a(n).at n=33A007209
- Irregular triangle read by rows: Whitney numbers of the second kind a(n,k), n >= 1, k >= 0, for the star poset.at n=41A007799
- Coordination sequence T1 for Zeolite Code AEL.at n=21A008004
- Coordination sequence T4 for Zeolite Code AFO.at n=21A008018
- Coordination sequence T2 for Zeolite Code AFT.at n=24A008027
- Coordination sequence T2 for Zeolite Code ATS.at n=23A008039
- Coordination sequence T2 for Zeolite Code DDR.at n=20A008072
- Molien series of 4-dimensional representation of cyclic group of order 4 over GF(2) (not Cohen-Macaulay).at n=27A008610
- Coordination sequence T3 for Zeolite Code RTH.at n=22A009895
- a(n) = floor(n*(n-1)*(n-2)/24).at n=30A011842