15481
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 15732
- Proper Divisor Sum (Aliquot Sum)
- 251
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15232
- Möbius Function
- 1
- Radical
- 15481
- Omega Function (Ω)
- 2
- 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
- 146
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- a(n) = prime(n)*prime(n+3).at n=29A090090
- Semiprimes in A056106.at n=25A113524
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, 0), (0, 0, 1), (1, -1, 1), (1, 1, -1)}.at n=9A148463
- a(n) = 12*n^2 + 22*n + 11.at n=35A154106
- Expansion of e.g.f. exp(x*sqrt(1+x^2)).at n=10A190863
- Number of arrays of -6..6 integers x(1..n) with every x(i) in a subsequence of length 1 or 2 with sum zero.at n=6A193646
- Number of arrays of median of three adjacent elements of some length-5 0..n array, with no adjacent equal elements in the latter.at n=23A229013
- Sequence of pairwise relatively prime numbers of class P_7 (see comment in A275246).at n=16A275252
- Numerators of fractions converging to limiting value of Galois polynomials.at n=4A280036
- Analog of Keith numbers based on digits of sum of anti-divisors.at n=9A284493
- Wiener index for the n-Andrásfai graph.at n=45A292018
- Number T(n,k) of ascent sequences of length n where the maximum of 0 and all letter multiplicities equals k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=48A294219
- G.f. A(x) satisfies: 1/(1 + x) = A(x)*A(x^2)^2*A(x^3)^3*A(x^4)^4* ... *A(x^k)^k* ...at n=35A307657
- Number of partitions of n in which exactly one odd part is repeated and even parts are unrestricted.at n=38A353903
- Numerator of the coefficient of x^(2n+1) in the Taylor series expansion of sin(sin(x)).at n=6A359553
- a(n) = Sum_{1 <= x_1, x_2, x_3, x_4 <= n} ( n/gcd(x_1, x_2, x_3, x_4, n) )^3.at n=3A372964