361
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 3
- Divisor Sum
- 381
- Proper Divisor Sum (Aliquot Sum)
- 20
- 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
- 342
- Möbius Function
- 0
- Radical
- 19
- Omega Function (Ω)
- 2
- 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
- yes
- 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
- 45
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- no
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- dreihunderteinundsechzig· ordinal: dreihunderteinundsechzigste
- English
- three hundred sixty-one· ordinal: three hundred sixty-first
- Spanish
- trescientos sesenta y uno· ordinal: 361º
- French
- trois cent soixante et un· ordinal: trois cent soixante et unième
- Italian
- trecentosessantuno· ordinal: 361º
- Latin
- trecenti sexaginta unus· ordinal: 361.
- Portuguese
- trezentos e sessenta e um· ordinal: 361º
Appears in sequences
- Nearest integer to modified Bessel function K_n(1).at n=5A000155
- n followed by n^2.at n=37A000463
- Expansion of e.g.f. sin(x)/cos(2*x).at n=2A000464
- Generalized tangent numbers d_(n,3).at n=1A000488
- Squares that are not the sum of 2 nonzero squares.at n=13A000548
- Expansion of Product_{k>=0} (1 + x^(2k+1)); number of partitions of n into distinct odd parts; number of self-conjugate partitions; number of symmetric Ferrers graphs with n nodes.at n=68A000700
- Expansion of (sin^2 x + sin x) /cos 2x.at n=5A000822
- Powers of 19.at n=2A001029
- Numbers k such that sum of squares of k consecutive integers >= 1 is a square.at n=41A001032
- Numbers n such that the sum of the squares of n consecutive positive odd numbers x^2 + (x+2)^2 + ... + (x+2n-2)^2 = k^2 for some integer k. The least values of x and k for each n are in A056131 and A056132, respectively.at n=26A001033
- Squares of primes.at n=7A001248
- Generalized Euler numbers, or Springer numbers.at n=5A001586
- Perfect powers: m^k where m > 0 and k >= 2.at n=26A001597
- a(n) = a(n-2) + a(n-5).at n=34A001687
- Powerful numbers, definition (1): if a prime p divides n then p^2 must also divide n (also called squareful, square full, square-full or 2-powerful numbers).at n=30A001694
- Quarter-squares: a(n) = floor(n/2)*ceiling(n/2). Equivalently, a(n) = floor(n^2/4).at n=38A002620
- Squares and cubes.at n=24A002760
- Numbers that are the sum of 11 positive 4th powers.at n=43A003345
- Number of perfect matchings (or domino tilings) in K_4 X P_n.at n=3A003769
- Primes written backwards.at n=37A004087