15403
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 15688
- Proper Divisor Sum (Aliquot Sum)
- 285
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15120
- Möbius Function
- 1
- Radical
- 15403
- 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
- "DGK" (bracelet, element, unlabeled) transform of 1,3,5,7,...at n=13A032234
- Numerators of convergents to Euler-Mascheroni constant.at n=10A046114
- Composite numbers which in base 6 contain their largest proper factor as a substring.at n=5A063156
- Duplicate of A063156.at n=5A063876
- Sum of the sizes of the Durfee squares of all partitions of n into odd parts.at n=50A116465
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k UDUDU's (n >= 0; 0 <= k <= n-2 for n >= 2).at n=50A128753
- Values of m such that A139361(n)=4m+1.at n=32A139362
- Numerator of Laguerre(n, -10).at n=5A160587
- Triangle read by rows: T(n,k) gives the number of ballot sequences of length n having exactly k descents, n>=0, 0<=k<=n.at n=83A238121
- Irregular triangle read by rows: T(n,k) gives the number of ballot sequences of length n having k descents, n>=0, 0<=k<=A083920(n-1).at n=48A238122
- Conjecturally, the largest k such that prime(n)^2 is the largest squared prime divisor of binomial(2k,k).at n=34A239623
- Number of partitions p of n such that (number of even numbers in p) < (number of odd numbers in p).at n=39A241636
- Number of ballot sequences of length n having exactly five descents.at n=3A241798
- a(n) is the least k such that A033273(k) is equal to (A033273(n*k + 1) - 1)/n where A033273(n) is the number of nonprime divisors of n.at n=32A352256
- Triangle T(n,k) read by rows (n >= 0, k >= 0) with g.f. 1/(1 - f(0)*x - x*y/(1 - f(1)*x - x*y/(1 - f(2)*x - x*y/(1 - f(3)*x - x*y/(1 - f(4)*x - x*y/(1 - ...)))))) where f(n) = n + 1 for n >= 0.at n=31A383019
- Number of integer compositions of n that are the first sums of some composition with all parts > 1.at n=40A391235