13494
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
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 29232
- Proper Divisor Sum (Aliquot Sum)
- 15738
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4128
- Möbius Function
- 1
- Radical
- 13494
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 182
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers k such that the k-th Euclid number A006862(k) = 1 + (Product of first k primes) is prime.at n=20A014545
- a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026615.at n=5A026959
- Number of proper factorizations of p1^n*p2^3, where p1 and p2 are distinct primes.at n=18A031126
- Molien series for 3-D group X1.at n=22A037240
- Numbers k such that 7*10^k + 1 is prime.at n=19A056804
- A088257 indexed by A002110.at n=35A088411
- Shadow of Euler's constant exp(1).at n=32A108912
- Numbers k such that 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)-1 and 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)+1 are twin primes with p(h) = h-th prime.at n=20A129311
- Number of lines through at least 2 points of a 7 X n grid of points.at n=35A160847
- Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=5A207238
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=41A207242
- Number of 6Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=3A207246
- Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0, 2, 5, 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0, 2, 5, 6 or 7.at n=6A252673
- T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 5 6 or 7.at n=34A252679
- Number of (7+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 5 6 or 7.at n=1A252686
- Square array read by antidiagonals upwards in which T(n,m) is the n-th number whose symmetric representation of sigma consists of m copies of unimodal pattern 121 (separated by 0's if m > 1).at n=31A372180