1604
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 2814
- Proper Divisor Sum (Aliquot Sum)
- 1210
- 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
- 800
- Möbius Function
- 0
- Radical
- 802
- Omega Function (Ω)
- 3
- 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
- 21
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Conjecturally largest even integer which is an unordered sum of two primes in exactly n ways.at n=23A000954
- Squares written in base 8.at n=29A002441
- Coordination sequence T3 for Zeolite Code EMT.at n=33A008088
- Coordination sequence T4 for Zeolite Code MFS.at n=25A008176
- Expansion of (1+x^7)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=47A008768
- Coordination sequence T3 for Zeolite Code VSV.at n=26A009916
- Phi(n) + 5 | sigma(n + 5).at n=22A015784
- Numbers k such that phi(k) + 10 | sigma(k + 10).at n=39A015789
- Continued fraction for log(63).at n=62A016491
- Expansion of 1/((1-x)*(1-3*x)*(1-4*x)*(1-8*x)).at n=3A021374
- Place where n-th 1 occurs in A023131.at n=33A022793
- Number of compositions of n into prime parts.at n=22A023360
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = A000201 (lower Wythoff sequence).at n=17A024464
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Fibonacci numbers), t = A000201 (lower Wythoff sequence).at n=16A025084
- a(n) = sum of the numbers between the two n's in A026370.at n=20A026373
- Positions of record values in A030737.at n=37A030742
- 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 20.at n=21A031518
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 20.at n=3A031698
- Decimal part of a(n)^(1/2) starts with reversal of its integer part: first term of runs.at n=24A034308
- Limit of the position of the n-th partition into parts 5k+1 or 5k+4 in the list of all integer partitions sorted in reverse lexicographic order, for integers == 0 (mod 5).at n=48A035405