1559
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1560
- 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
- 1558
- Möbius Function
- -1
- Radical
- 1559
- 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
- 60
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 246
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) is the least number m such that the n-th prime is the least quadratic nonresidue modulo m.at n=6A000229
- a(n) = round(sqrt( 2*Pi )^n).at n=8A001675
- a(n) = ceiling(sqrt( 2*Pi )^n).at n=8A001698
- Erroneous version of A045535.at n=5A001984
- Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1.at n=25A002146
- Smallest prime p of form p = 8k-1 such that first n primes (p_1=2, ..., p_n) are quadratic residues mod p.at n=5A002223
- Primes of the form k^2 - k - 1.at n=22A002327
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=27A002515
- Sophie Germain primes p: 2p+1 is also prime.at n=51A005384
- Prime self (or Colombian) numbers: primes not expressible as the sum of an integer and its digit sum.at n=27A006378
- Primes of form x^3 + y^3 + z^3 where x,y,z > 0.at n=38A007490
- Coordination sequence T1 for Zeolite Code BOG.at n=28A008049
- Coordination sequence T2 for Zeolite Code BOG.at n=28A008050
- Coordination sequence T4 for Zeolite Code BOG.at n=28A008052
- Coordination sequence T1 for Zeolite Code -CHI.at n=25A009846
- Largest convex area that can be tiled with n equilateral triangles whose sides s_k are relatively prime, i.e., gcd(s_1,...,s_n) = 1.at n=12A014529
- Numbers k such that phi(k + 13) | sigma(k).at n=47A015833
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MEL = ZSM-11 Nan[AlnSi96-nO192] starting with a T6 atom.at n=10A019154
- Numbers k such that the continued fraction for sqrt(k) has period 28.at n=24A020367
- Number of nonisomorphic cyclic subgroups of alternating group A_n (or number of distinct orders of even permutations of n objects); number of different LCM's of partitions of n which have even number of even parts.at n=57A020902