11639
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11856
- Proper Divisor Sum (Aliquot Sum)
- 217
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11424
- Möbius Function
- 1
- Radical
- 11639
- 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
- 143
- 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
- n-th 4k+1 prime times n-th 4k-1 prime.at n=13A048630
- Composite numbers n such that sigma(n+24) = sigma(n) + 24.at n=17A054983
- a(n) = Sum_{d|n} phi(d^3).at n=22A068963
- a(n) = least semiprime with factors not previously used containing integers 2n and 2n+1 as substrings.at n=5A086887
- a(n) = prime(n)*prime(n+3).at n=26A090090
- a(n) = n^3 - n^2 + 1.at n=23A100104
- Number of parts in all partitions of n in which no part occurs more than 3 times.at n=28A117148
- a(n) = pq + pr + qr with p = prime(n), q = prime(n+1), and r = prime(n+2).at n=16A127345
- Composites in A127345.at n=7A127347
- Maximal number of right triangles in n turns of Pythagoras's snail.at n=33A137515
- Numbers k such that 2*k+1, 3*k+2, 4*k+3 and 5*k+4 are primes.at n=15A138700
- a(n) = 529*n + 1.at n=21A158368
- a(n) = 22*n^2 + 1.at n=23A158537
- Number of 0..7 arrays of length n with each element unequal to at least one neighbor, with new values introduced in 0..7 order.at n=8A221458
- S_9 sequence in partition of integers > 1 described in A240521.at n=32A240536
- a(n) = position of the first occurrence of n in A245714.at n=20A245723
- Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 1 3 6 or 7.at n=3A252304
- Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7.at n=6A252309
- Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly three bit positions.at n=30A261075
- Sequence of pairwise relatively prime numbers of class P_6 (see comment in A275246).at n=14A275251