13719
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19440
- Proper Divisor Sum (Aliquot Sum)
- 5721
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8576
- Möbius Function
- -1
- Radical
- 13719
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 63
- 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
- a(n) = 2*n^3 + 1.at n=19A033562
- Numerators of continued fraction convergents to sqrt(665).at n=9A042278
- Numbers k such that k^18 == 1 (mod 19^3).at n=36A056089
- Numbers n such that (Pi/sqrt(2))^n is closer to its nearest integer than any value of (Pi/sqrt(2))^k for 1 <= k < n.at n=15A095203
- Partial sums of A002522, starting at n=1.at n=33A145066
- a(n) = 392*n - 1.at n=34A158004
- a(n) = 361*n + 1.at n=37A158310
- a(n) = 38*n^2 + 1.at n=19A158593
- a(n) = 70*n^2 - 1.at n=13A158736
- Numbers k such that Sum_{i=1..k} i^7 divides Product_{i=1..k} i^7.at n=10A166607
- A permutation pi on [1,2,....n] has k(pi) longest increasing subsequences associated with it; 1<= k(pi)<= f(n) for some function f. The given sequence enumerates sum_pi k(pi).at n=6A167999
- Ascending sequence of numbers such that the sum of any two distinct elements (even + odd) is a prime number.at n=32A180743
- Number of partitions p of n such that max(p)-min(p) = 8.at n=39A218571
- Expansion of chi(x)^2 / chi(-x^2)^6 in powers of x where chi() is a Ramanujan theta function.at n=16A224916
- Numbers whose squares become cubes if one of their digits is deleted.at n=33A245096
- Number of n X 3 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.at n=21A253218
- Number of positive subset sums of strict integer partitions of n.at n=35A284640
- Numerator of best rational approximation x/y of sqrt(k), y<=k, with k given by A306972. The corresponding denominators are given in A306974.at n=30A306973
- Number of partitions of n with seven parts in which no part occurs more than twice.at n=42A320595