2695
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 4104
- Proper Divisor Sum (Aliquot Sum)
- 1409
- 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
- 1680
- Möbius Function
- 0
- Radical
- 385
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 27
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = Sum_{k=1..n-1} k*sigma(k)*sigma(n-k).at n=10A000441
- Numbers k such that phi(k) = phi(k+2).at n=43A001494
- a(n) = (8*n+1)*(8*n+7).at n=6A001533
- 4-dimensional figurate numbers: a(n) = (5*n-1)*binomial(n+2,3)/4.at n=10A002418
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 3.at n=33A013591
- Composite numbers that are equal to the sum of the first k composites for some k.at n=47A013921
- Numbers k that divide s(k), where s(1)=1, s(j)=15*s(j-1)+j.at n=26A014865
- a(n) = 49*(n-1)*(n-2)/2.at n=9A027469
- "DHK" (bracelet, identity, unlabeled) transform of 2,2,2,2,...at n=10A032251
- Number of partitions of n into parts not of the form 17k, 17k+5 or 17k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 7 are greater than 1.at n=28A035966
- Number of partitions of n into parts not of the form 19k, 19k+7 or 19k-7. Also number of partitions with at most 6 parts of size 1 and differences between parts at distance 8 are greater than 1.at n=27A035976
- Numbers whose prime factors are in {5, 7, 11}.at n=26A036490
- Transformation of A036490: 5^a*7^b*11^c -> 5^a*7^floor((b+2)/2)*11^c.at n=45A036491
- Transformation of A036490: 5^a*7^b*11^c -> 5^a*7^floor((b+2)/2)*11^c.at n=26A036491
- Number of partitions of n such that cn(0,5) = cn(1,5) = cn(3,5) <= cn(2,5) = cn(4,5).at n=72A036866
- Number of partitions of n such that cn(0,5) = cn(1,5) = cn(3,5) < cn(2,5) = cn(4,5).at n=72A036869
- Numerators of continued fraction convergents to sqrt(123).at n=2A041222
- Numbers whose base-7 representation contains exactly three 0's.at n=23A043395
- Numbers n such that string 0,7 occurs in the base 8 representation of n but not of n-1.at n=46A044194
- Numbers n such that string 2,4 occurs in the base 9 representation of n but not of n-1.at n=37A044273