6635
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7968
- Proper Divisor Sum (Aliquot Sum)
- 1333
- 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
- 5304
- Möbius Function
- 1
- Radical
- 6635
- 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
- 75
- 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
- Dying rabbits: a(n) = a(n-1) + a(n-2) - a(n-12).at n=20A023442
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2.at n=13A049937
- Gregorian calendar years with Ascension Day in April.at n=22A084427
- Riordan array (f(x), x*f(x)) where f(x) is the g.f. of A126931.at n=40A171509
- Rank of 2^n when all prime powers (A246655) p^n, for n>=1, are jointly ranked.at n=15A182908
- Numbers k such that there are 14 primes between 100*k and 100*k + 99.at n=29A186406
- Numbers congruent to 3 in the structure (or curve) of A211000.at n=42A211002
- Count of the first 10^n primes which do not contain the digit 5.at n=4A228417
- Number of arrays of median of three adjacent elements of some length n+2 0..6 array, with no adjacent equal elements in the latter.at n=4A229010
- T(n,k) = number of arrays of median of three adjacent elements of some length n+2 0..k array, with no adjacent equal elements in the latter.at n=49A229012
- Number of arrays of median of three adjacent elements of some length 7 0..n array, with no adjacent equal elements in the latter.at n=5A229015
- Indices of primes in A214828.at n=17A242572
- Partial sums of A072272.at n=50A253908
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 422", based on the 5-celled von Neumann neighborhood.at n=32A272087
- Binomial transform of A023871.at n=7A294530
- Number of multisets of exactly four partitions of positive integers into distinct parts with total sum of parts equal to n.at n=18A320789
- Sum of the third largest parts r of the partitions of n into 4 parts q,r,s,t such that 1 <= q <= r <= s <= t and q + r + s > t.at n=54A340247
- Discriminants of imaginary quadratic fields with class number 30 (negated).at n=29A351668
- Indices of consecutive prime-powers (exclusive) differing by 1. Positions of 1's in A057820.at n=10A375734
- Position of first appearance of n in A057820, the sequence of first differences of prime-powers, or 0 if n does not appear.at n=14A376341