13423
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13888
- Proper Divisor Sum (Aliquot Sum)
- 465
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12960
- Möbius Function
- 1
- Radical
- 13423
- 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
- 213
- 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
- Denominators of continued fraction convergents to sqrt(173).at n=6A041319
- Semiprimes k=p*q such that the polynomial (1+x)^k (mod k) has p+q nonzero terms.at n=42A116926
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-0111-0100 pattern in any orientation.at n=10A146464
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0111-0100 pattern in any orientation.at n=22A146466
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0111-0100 pattern in any orientation.at n=23A146466
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 00100-00100-11111 pattern in any orientation.at n=11A147002
- First differences of A003591.at n=62A165742
- Number of strings of numbers x(i=1..n) in 0..2 with sum i*x(i)^2 equal to n*4.at n=16A184434
- Monotonic ordering of nonnegative differences 2^i-7^j, for 40>=i>=0, j>=0.at n=38A192118
- a(n) = n*(14*n - 1).at n=31A195024
- Number of practical numbers between powers of 2 where the practical numbers are A005153.at n=17A214932
- Lesser of 2 successive squarefree semiprimes (k, k+4) sandwiching 3 consecutive nonsquarefree numbers.at n=37A363821
- Expansion of 1/( (1 + x)^2 * (1 - x^2*(1 + x)^3) ).at n=18A375365