2591
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
- 2
- Divisor Sum
- 2592
- 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
- 2590
- Möbius Function
- -1
- Radical
- 2591
- 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
- 53
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 377
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=25A000099
- Number of centered 3-valent (or boron, or binary) trees with n nodes.at n=17A000675
- Primes with 7 as smallest primitive root.at n=23A001126
- Artiads: the primes p == 1 (mod 5) for which Fibonacci((p-1)/5) is divisible by p.at n=15A001583
- Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1.at n=28A002146
- Class 1+ primes: primes of the form 2^i*3^j - 1 with i, j >= 0.at n=20A005105
- Primes of the form k^2 + k + 41.at n=46A005846
- Number of factorization patterns of polynomials of degree n over F_5.at n=15A006170
- Coordination sequence T2 for Zeolite Code LOV.at n=34A008135
- Coordination sequence T2 for Zeolite Code MEI.at n=37A008147
- Let S(x,y) = number of lattice paths from (0,0) to (x,y) that use the step set { (0,1), (1,0), (2,0), (3,0), ...} and never pass below y = x. Sequence gives S(n-1,n) = number of 'Schröder' trees with n+1 leaves and root of degree 2.at n=6A010683
- Triangle of numbers S(x,y) = number of lattice paths from (0,0) to (x,y) that use step set { (0,1), (1,0), (2,0), (3,0), ....} and never pass below y = x.at n=34A011117
- Next prime after n-th Fibonacci number.at n=18A014208
- Super-3 Numbers (3n^3 contains substring '333' in its decimal expansion).at n=21A014569
- Indices of prime Mersenne numbers (A001348).at n=25A016027
- Coordination sequence T1 for Zeolite Code CZP.at n=33A019456
- Numbers k such that the continued fraction for sqrt(k) has period 48.at n=17A020387
- Greatest prime divisor of prime(n)*prime(n-1) - 1.at n=19A023517
- Least odd prime divisor of prime(n)*prime(n-1) - 1, or 1 if prime(n)*prime(n-1) - 1 is a power of 2.at n=20A023519
- Numbers whose least quadratic nonresidue (A020649) is 7.at n=36A025023