2531
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2532
- 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
- 2530
- Möbius Function
- -1
- Radical
- 2531
- 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
- 40
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 370
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Squares written in base 8.at n=36A002441
- Coordination sequence T1 for Zeolite Code AHT.at n=34A009866
- a(n) is the sum over all floor(k^3/n), k=0 to n inclusive.at n=20A014818
- Number of parts in all partitions of all the numbers in {1,2,...,n} into distinct parts.at n=23A015724
- Numbers k such that the continued fraction for sqrt(k) has period 58.at n=3A020397
- Primes that remain prime through 2 iterations of the function f(x) = 5x + 4.at n=23A023253
- Primes that remain prime through 3 iterations of function f(x) = 5x + 4.at n=9A023284
- Greatest prime divisor of prime(n)*prime(n-1) - 1.at n=47A023517
- a(n) = T(n,0) + T(n,1) + ... + T(n,[ n/2 ]), T given by A026703.at n=10A026711
- Expansion of (1+x^2-x^3)/(1-x)^4.at n=22A027378
- Palindromic primes in base 15.at n=28A029982
- Primes which when concatenated with next 3 primes are also prime.at n=27A030472
- a(n) = prime(10*n).at n=36A031343
- 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 49.at n=9A031547
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 24 ones.at n=18A031792
- a(n) = prime(9*n-8).at n=41A031918
- Lower prime of a difference of 8 between consecutive primes.at n=32A031926
- Upper prime of a difference of 10 between consecutive primes.at n=34A031929
- Concentric pentagonal numbers: floor( 5*n^2 / 4 ).at n=45A032527
- Concatenation of n and n + 6 or {n,n+6}.at n=24A032611