1637
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1638
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 1636
- Möbius Function
- -1
- Radical
- 1637
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 42
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 259
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = least value of m for which Liouville's function A002819(m) = -n.at n=43A002053
- Divisible only by primes congruent to 6 mod 7.at n=47A004624
- a(n) = smallest number k such that Product_{i=1..k} prime(i)/(prime(i)-1) > n.at n=17A005579
- Spiral sieve using Fibonacci numbers.at n=15A005620
- Primes of form x^3 + y^3 + z^3 where x,y,z > 0.at n=40A007490
- Molien series for Conway group Con.0.at n=32A008925
- a(n) = n^2 + 3*n - 1.at n=39A014209
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite CHI = Chiavennite Ca4Mn4[Be8Si20O52(OH)8].8H2O starting with a T4 atom.at n=12A019094
- Numbers k such that the continued fraction for sqrt(k) has period 21.at n=12A020360
- Primes p such that 7*p + 8 is also prime.at n=47A023226
- Primes that remain prime through 2 iterations of the function f(x) = 5x + 6.at n=46A023254
- Primes that remain prime through 2 iterations of function f(x) = 8x + 7.at n=18A023263
- Primes that remain prime through 2 iterations of function f(x) = 9x + 4.at n=29A023266
- Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=11A023297
- Primes that remain prime through 4 iterations of function f(x) = 9x + 4.at n=5A023325
- Convolution of A023532 and (1, p(1), p(2), ...).at n=34A023598
- Convolution of A023532 and primes.at n=33A023606
- Numbers that are the sum of 3 nonzero squares in exactly 9 ways.at n=38A025329
- Numbers that are the sum of 3 distinct nonzero squares in exactly 9 ways.at n=22A025347
- Index of 6^n within the sequence of the numbers of the form 3^i*6^j.at n=44A025713