1655
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
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1992
- Proper Divisor Sum (Aliquot Sum)
- 337
- 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
- 1320
- Möbius Function
- 1
- Radical
- 1655
- 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
- 42
- 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
- Numbers that are the sum of 10 positive 6th powers.at n=24A003366
- a(n) = 3*n^2 + 3*n - 1.at n=23A004538
- a(n) = round(n*phi^7), where phi is the golden ratio, A001622.at n=57A004942
- a(n) = ceiling(n*phi^7), where phi is the golden ratio, A001622.at n=57A004962
- Record values in A005210.at n=44A005211
- Numbers n such that 8*3^n + 1 is prime.at n=14A005538
- Oscillates under partition transform.at n=34A007210
- Number of ordered quadruples of integers from [ 1,n ] with no common factors between pairs.at n=23A015636
- Place where n-th 1 occurs in A023129.at n=44A022791
- Numbers k such that Fibonacci(k) == 5 (mod k).at n=49A023176
- Position of n^2 + 5 in A000408.at n=44A024801
- a(n) = position of n^2 + (n+1)^2 + (n+2)^2 in A000408.at n=24A024802
- a(n) = T(n, 2n-3), T given by A027023.at n=7A027027
- a(n) = greatest number in row n of array T given by A027023.at n=9A027039
- Sequence satisfies T^2(a)=a, where T is defined below.at n=49A027584
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 16.at n=38A031514
- Number of matchings in graph C_{3} X P_{n}.at n=4A033515
- a(n) = 2*n^2 + 3*n + 3.at n=28A033816
- Number of partitions of n with equal number of parts congruent to each of 1 and 2 (mod 4).at n=36A035543
- Number of partitions in parts not of the form 13k, 13k+1 or 13k-1. Also number of partitions with no part of size 1 and differences between parts at distance 5 are greater than 1.at n=33A035949