1511
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1512
- 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
- 1510
- Möbius Function
- -1
- Radical
- 1511
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 91
- 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
- 240
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p == 3, 9, 11 (mod 20) such that 2p+1 is also prime.at n=25A000355
- Smallest prime p such that the product of q/(q-1) over the primes from prime(n) to p is greater than 2.at n=11A001275
- Artiads: the primes p == 1 (mod 5) for which Fibonacci((p-1)/5) is divisible by p.at n=10A001583
- Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1.at n=24A002146
- Squares written in base 8.at n=28A002441
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=26A002515
- a(n) = a(n-1) + 2*a(n-3) with a(0)=a(1)=1, a(2)=3.at n=14A003229
- Numbers that are the sum of 4 positive 5th powers.at n=22A003349
- Divisible only by primes congruent to 6 mod 7.at n=43A004624
- Numbers that are the sum of at most 4 positive 5th powers.at n=52A004844
- Sophie Germain primes p: 2p+1 is also prime.at n=50A005384
- Cald's sequence: a(n+1) = a(n) - prime(n) if that value is positive and new, otherwise a(n) + prime(n) if new, otherwise 0; start with a(1)=1.at n=113A006509
- Balanced primes (of order one): primes which are the average of the previous prime and the following prime.at n=20A006562
- Numbers n such that n, 2n+1, and 4n+3 all prime.at n=15A007700
- Coordination sequence T4 for Zeolite Code EUO.at n=24A008099
- Coordination sequence T1 for Zeolite Code NAT.at n=26A008203
- Coordination sequence T1 for Zeolite Code NES.at n=25A008205
- Expansion of (1+x^12)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=48A008773
- Magnetic susceptibility coefficients for square lattice spin 3/2 Ising model.at n=24A010118
- Numbers k such that phi(k + 13) | sigma(k).at n=45A015833