756
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 2240
- Proper Divisor Sum (Aliquot Sum)
- 1484
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 216
- Möbius Function
- 0
- Radical
- 42
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 3
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
- yes
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 108
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Names
- German
- siebenhundertsechsundfünfzig· ordinal: siebenhundertsechsundfünfzigste
- English
- seven hundred fifty-six· ordinal: seven hundred fifty-sixth
- Spanish
- setecientos cincuenta y seis· ordinal: 756º
- French
- sept cent cinquante-six· ordinal: sept cent cinquante-sixième
- Italian
- settecentocinquantasei· ordinal: 756º
- Latin
- septingenti quinquaginta sex· ordinal: 756.
- Portuguese
- setecentos e cinquenta e seis· ordinal: 756º
Appears in sequences
- Number of primitive polynomials of degree n over GF(2) (version 2).at n=13A000020
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); A000092 gives values of n where |P(n)| sets a new record; sequence gives (nearest integer to, I believe) P(A000092(n)).at n=28A000223
- Boustrophedon transform of natural numbers, cf. A000027.at n=6A000737
- Number of forests with n nodes and height at most 2.at n=5A000949
- Smallest even number that is an unordered sum of two odd primes in exactly n ways.at n=35A001172
- Numbers that are the sum of 4 cubes in more than 1 way.at n=44A001245
- Oblong (or promic, pronic, or heteromecic) numbers: a(n) = n*(n+1).at n=27A002378
- Number of integral points in a certain sequence of open quadrilaterals.at n=43A002578
- Quarter-squares: a(n) = floor(n/2)*ceiling(n/2). Equivalently, a(n) = floor(n^2/4).at n=55A002620
- Expansion of (1-x)^(-3) * (1-x^2)^(-2).at n=13A002624
- a(n) = 2*n*(2*n-1).at n=14A002939
- Beginnings of periodic unitary aliquot sequences.at n=61A003062
- Numbers that are the sum of 2 positive cubes.at n=36A003325
- a(n) = a(n-1) + a(n-5); a(0) = ... = a(4) = 1.at n=26A003520
- Smallest positive integer that is n times its digit sum, or 0 if no such number exists.at n=41A003634
- Expansion of theta series of {E_7}* lattice in powers of q^(1/2).at n=8A003781
- Numbers that are a sum of distinct positive cubes in more than one way.at n=13A003998
- Expansion of theta series of E_7 lattice in powers of q^2.at n=2A004008
- Theta series of 12-dimensional Coxeter-Todd lattice K_12.at n=2A004010
- Theta series of 14-dimensional extremal 3-modular lattice with det 3^7, minimal norm 4, group 2 X G_2(3).at n=2A004048