15119
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16296
- Proper Divisor Sum (Aliquot Sum)
- 1177
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13944
- Möbius Function
- 1
- Radical
- 15119
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 133
- 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
- Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=37A000099
- a(n) = ( Sum C(p,i); i=1,...,floor(2p/3) ) / p^2, where p = prime(n).at n=6A001007
- Numbers having four 5's in base 6.at n=33A043392
- Numbers k such that A055079(k) = 2^k.at n=33A057838
- First of triples of consecutive happy numbers, i.e., the first of three consecutive integers each of which is a happy number (A007770).at n=18A072494
- Least m which can be written as i*j+i+j in n different ways: A072670(m)=n.at n=39A072671
- First column of A083798.at n=11A083800
- Row sums of triangle A097094 and also equals the self-convolution of A097097 (antidiagonal sums of triangle A097094).at n=16A097096
- Numbers k such that either k or k+1 is divisible by the numbers from 1 to 10.at n=22A131663
- Square root of squares in A145768 (XOR of squares of the numbers 1..n).at n=37A145829
- Composites c where |c-m| = 1, where m is any of the smallest positive integers with their number of divisors. (m belongs to sequence A007416.)at n=42A152246
- Numbers m such that m mod k is k-1 for all k = 2..9.at n=5A166931
- a(n) = 3*n! - 1.at n=7A173323
- a(1)=1. a(n) = the smallest integer > a(n-1) such that d(a(n))+d(a(n)+1) > d(a(n-1))+d(a(n-1)+1), where d(m) = the number of divisors of m.at n=37A175143
- A symmetrical triangle sequence:t(n,m)=(-1)^m*(n - m)!*Binomial[n - 1, m] + (-1)^(n - m + 1)*(n - (n - m + 1))!*Binomial[n - 1, n - m + 1].at n=15A176862
- A symmetrical triangle sequence:t(n,m)=(-1)^m*(n - m)!*Binomial[n - 1, m] + (-1)^(n - m + 1)*(n - (n - m + 1))!*Binomial[n - 1, n - m + 1].at n=20A176862
- Expansion of 1/(1 - x - x^2 + x^8 - x^10).at n=21A181600
- Negabinary Keith numbers.at n=17A188381
- Auxiliary c(n) sequence used to prove some properties about Rowland's sequence. c(n) has the following recursive definition: c(1) = 5, c_(n+1) = c(n) + lfp(c(n)) - 1, where lpf(.) denotes the lowest prime factor of a number.at n=31A190894
- Smallest number requiring n terms to be expressed as a sum of factorials.at n=23A200748