1271
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
- 4
- Divisor Sum
- 1344
- Proper Divisor Sum (Aliquot Sum)
- 73
- 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
- 1200
- Möbius Function
- 1
- Radical
- 1271
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 31
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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(1) = 0, a(2) = -2; for n > 2, a(n) + a(n-2) - a(n-3) - a(n-5) - ... - a(n-p) = (-1)^(n+1)*n if n is prime, otherwise = 0, where p = largest prime < n.at n=37A002120
- Numerators of coefficients for central differences M_{4}^(2*n).at n=9A002675
- Numerators of the Taylor coefficients of (e^x-1)^2.at n=19A002678
- Numbers that are the sum of 6 positive 5th powers.at n=33A003351
- Divisors of 2^20 - 1.at n=25A003529
- Divisors of 2^40 - 1.at n=35A003546
- Odd numbers not of form p + 2^k (de Polignac numbers).at n=25A006285
- Coordination sequence T2 for Zeolite Code DOH.at n=22A008079
- Coordination sequence T1 for Zeolite Code ERI and OFF.at n=26A008093
- Coordination sequence T5 for Zeolite Code EUO.at n=22A008100
- Coordination sequence T7 for Zeolite Code EUO.at n=22A008102
- Coordination sequence T3 for Zeolite Code MOR.at n=23A008184
- Coordination sequence T1 for Coesite.at n=19A008267
- Composite but smallest prime factor >= 17.at n=41A008367
- Expansion of (1+x^4)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=42A008765
- Coordination sequence for MgNi2, Position Mg2.at n=9A009935
- a(n) = floor(binomial(n,9)/9).at n=16A011855
- a(n) = prevprime(n)*nextprime(n).at n=34A013638
- Composite numbers that are equal to the sum of the first k composites for some k.at n=32A013921
- Positive integers n such that 2^n == 2^11 (mod n).at n=32A015935