15493
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15494
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15492
- Möbius Function
- -1
- Radical
- 15493
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 53
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1809
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 8x + 9.at n=9A023295
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 72 ones.at n=21A031840
- Upper prime of a difference of 20 between consecutive primes.at n=31A031939
- Numerators of continued fraction convergents to sqrt(861).at n=5A042662
- Numbers whose base-5 representation contains exactly three 3's and three 4's.at n=18A045307
- Number of mobiles (circular rooted trees) with n nodes and 6 leaves.at n=7A055344
- Smallest prime of the form (prime(n)*prime(n+1)+q)/2 for some integer n and some prime q.at n=38A100557
- Number of partitions of n in which the sequence of frequencies of the summands is nondecreasing.at n=40A100883
- Primes of the form A108656(n-2)*n^2+A108656(n-1)*n+A108656(n).at n=29A108657
- Odd terms of A059756.at n=13A111042
- Primes congruent to 13 mod 43.at n=40A142262
- Primes congruent to 30 mod 47.at n=38A142381
- Primes congruent to 17 mod 53.at n=37A142547
- Primes congruent to 35 mod 59.at n=33A142762
- Primes congruent to 60 mod 61.at n=26A142858
- 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, -1), (-1, 0, 0), (1, -1, 0), (1, 0, 1), (1, 1, -1)}.at n=9A148837
- Irregular triangle T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1-x)^(2*n+3)*( Sum_{j >= 0} (2*j+ 1)^n*x^j )*( Sum_{j >= 0} j^(n+1)*x^j ), read by rows.at n=27A165883
- Irregular triangle T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1-x)^(2*n+3)*( Sum_{j >= 0} (2*j+ 1)^n*x^j )*( Sum_{j >= 0} j^(n+1)*x^j ), read by rows.at n=33A165883
- 3-comma numbers: n occurs in the sequence S[k+1]=S[k]+10*last_digit(S[k-1])+first_digit(S[k]) for three different splittings n=concat(S[0],S[1]).at n=15A166513
- Triangle T(n,k) read by rows: T(n,k) = Sum_{j=0..k} (-1)^j *binomial(n+1,j)*(k+2-j)^n, 0 <= k < n.at n=31A180246