11837
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
- 8
- Divisor Sum
- 14400
- Proper Divisor Sum (Aliquot Sum)
- 2563
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9504
- Möbius Function
- -1
- Radical
- 11837
- 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
- yes
- 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
- 99
- 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
- Odd pentagonal numbers.at n=44A014632
- Pseudoprimes to base 20.at n=34A020148
- Pentagonal numbers with odd index: a(n) = (2*n+1)*(3*n+1).at n=44A033570
- Number of partitions satisfying cn(2,5) <= cn(0,5) + cn(3,5) and cn(2,5) <= cn(0,5) + cn(4,5) and cn(3,5) <= cn(0,5) + cn(1,5) and cn(3,5) <= cn(0,5) + cn(4,5).at n=39A039875
- Pentagonal numbers (A000326) whose digit reversal is a semiprime (A001358).at n=25A115709
- Pentagonal numbers with prime indices.at n=23A116995
- Number of essentially different semi-magic squares of order 3 with semimagic sum n.at n=27A122751
- Number of distinct solutions of sum{i=1..2}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 2..n-2.at n=48A180825
- Number of 3 X n 0..3 arrays with no element equal to zero plus the sum of elements to its left or two plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.at n=23A239987
- Nonsemiprimes in A306097 = A121707 \ A267999.at n=11A321488
- a(n) = Sum_{k=0..floor((n-1)/3)} |Stirling1(n,3*k+1)|.at n=8A357829
- Pentagonal numbers which are products of three distinct primes.at n=22A381650