8137
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8320
- Proper Divisor Sum (Aliquot Sum)
- 183
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7956
- Möbius Function
- 1
- Radical
- 8137
- 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
- 158
- 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
- Pseudoprimes to base 56.at n=36A020184
- Numbers k such that the continued fraction for sqrt(k) has period 80.at n=26A020419
- "CFK" (necklace, size, unlabeled) transform of 1,3,5,7...at n=13A032142
- Number of partitions satisfying cn(2,5) + cn(3,5) <= cn(1,5) + cn(4,5).at n=33A039895
- a(n) = lcm(A051612(n), A065387(n)), where A051612(n) = sigma(n) - phi(n) and A065387(n) = sigma(n) + phi(n).at n=35A077100
- a(n) = A051612(n)*A065387(n) = sigma(n)^2-phi(n)^2, where A051612(n) = sigma(n) - phi(n) and A065387(n) = sigma(n) + phi(n).at n=35A077101
- Smallest number whose cube begins and ends in n, or 0 if no such number exists.at n=53A077752
- Number of triangular partitions of n of order 3.at n=27A084439
- Smallest m such that A098371(m) = n.at n=30A098373
- Number of partitions of 2*n into minimal numbers.at n=36A099385
- Least j > 1 such that j^2 = (4*n^2 + 2)*(k^2) + (4*n^2 + 2)*k + 1.at n=12A106231
- Products of two primes that are not Chen primes.at n=20A115719
- Start with 1 and repeatedly reverse the digits and add 63 to get the next term.at n=12A118158
- Start with 1 and repeatedly reverse the digits and add 63 to get the next term.at n=42A118158
- Start with 1 and repeatedly reverse the digits and add 36 to get the next term.at n=9A118536
- a(1)=1. a(n+1) = Sum_{k=1..n} a(b(k,n)), where b(k,n) is the largest positive integer that, when written in binary, occurs as a substring in both binary k and binary n.at n=35A175491
- Numbers arising from certain regular binary expansions.at n=13A175879
- Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=13A192972
- Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of (f(i,j)), where f(i,1)=f(1,j)=1, f(i,i)= i; f(i,j)=0 otherwise; as in A204179.at n=29A204180
- a(n) is the first occurrence of n in sequence A209266.at n=24A211389