11387
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11640
- Proper Divisor Sum (Aliquot Sum)
- 253
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11136
- Möbius Function
- 1
- Radical
- 11387
- 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
- 174
- 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
- Consider all integer triples (i,j,k), j >= k > 0, with binomial(i+2,3) = j^3 + k^3, ordered by increasing i; sequence gives i values.at n=9A054205
- Numbers n such that n = pi(d_1!!*d_2!!*...*d_k!!) where d_1 d_2 ... d_k is the decimal expansion of n.at n=3A110071
- Number of permutations of length n which avoid the patterns 312, 1324, 3421; or avoid the patterns 312, 1324, 2341, etc.at n=23A116722
- a(n) = Fibonacci(n) + n^2.at n=21A160536
- G.f.: exp( Sum_{n>=1} sigma(2n)*x^n/n ).at n=14A182818
- Number of strictly increasing arrangements of 6 nonzero numbers in -(n+4)..(n+4) with sum zero.at n=11A188125
- Concatenate the n-th prime with the n-th semiprime.at n=29A262428
- a(n) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4), where a(0) = 2, a(1) = 4, a(2) = 5, a(3) = 6.at n=23A288429
- Partial sums of A323183.at n=36A323187
- Expansion of Sum_{k>=1} x^k / (1 - k * x^k)^k.at n=21A324158
- Numbers k such that A361338(k) = 8.at n=35A361347
- a(n) = Sum_{d|n} d^(n/d) * binomial(n/d-1,d-1).at n=17A376020