731
domain: N
Properties
Digital Properties
- Digit Count
- 3
- 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
- 792
- Proper Divisor Sum (Aliquot Sum)
- 61
- 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
- 672
- Möbius Function
- 1
- Radical
- 731
- 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
- 139
- Smith 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
Names
- German
- siebenhunderteinunddreißig· ordinal: siebenhunderteinunddreißigste
- English
- seven hundred thirty-one· ordinal: seven hundred thirty-first
- Spanish
- setecientos treinta y uno· ordinal: 731º
- French
- sept cent trente et un· ordinal: sept cent trente et unième
- Italian
- settecentotrentuno· ordinal: 731º
- Latin
- septingenti triginta unus· ordinal: 731.
- Portuguese
- setecentos e trinta e um· ordinal: 731º
Appears in sequences
- a(n) = a(n-1)^3 + a(n-2) with a(0)=0, a(1)=1.at n=5A000284
- Number of partitions of n in which no parts are multiples of 3.at n=27A000726
- Number of inequivalent planar partitions of n, when considering them as 3D objects.at n=14A000786
- Numbers k such that (k^2 + k + 1)/13 is prime.at n=34A002642
- Number of self-dual binary codes of length 2n (up to column permutation equivalence).at n=15A003179
- Numbers that are the sum of 5 positive 5th powers.at n=15A003350
- Numbers that are the sum of 3 nonzero 6th powers.at n=4A003359
- Numbers of the form 2^j + 3^k, for j and k >= 0.at n=55A004050
- Primes written backwards.at n=32A004087
- Numbers that are the sum of at most 5 positive 5th powers.at n=48A004845
- Numbers that are the sum of at most 3 nonzero 6th powers.at n=12A004854
- Numbers that are the sum of at most 4 nonzero 6th powers.at n=17A004855
- Numbers that are the sum of at most 5 nonzero 6th powers.at n=23A004856
- Numbers that are the sum of at most 6 nonzero 6th powers.at n=30A004857
- Numbers that are the sum of at most 7 nonzero 6th powers.at n=38A004858
- Numbers that are the sum of at most 8 nonzero 6th powers.at n=47A004859
- a(n) = n*(5*n+1)/2.at n=17A005475
- The limiting sequence [A259095(r(r+1)/2-s,r), s=0,1,2,...,r-1] for very large r.at n=23A005576
- Binomial transform of Catalan numbers.at n=6A007317
- a(n) = n OR n^2 (applied to binary expansions).at n=26A007745