127
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
- 2
- Divisor Sum
- 128
- 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
- 126
- Möbius Function
- -1
- Radical
- 127
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- yes
- 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
- 46
- Smith Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- yes
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 31
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- einshundertsiebenundzwanzig· ordinal: einshundertsiebenundzwanzigste
- English
- one hundred twenty-seven· ordinal: one hundred twenty-seventh
- Spanish
- ciento veintisiete· ordinal: 127º
- French
- cent vingt-sept· ordinal: cent vingt-septième
- Italian
- centoventisette· ordinal: 127º
- Latin
- centum viginti septem· ordinal: 127.
- Portuguese
- cento e vinte e sete· ordinal: 127º
Appears in sequences
- Let k = p_1^e_1 p_2^e_2 p_3^e_3 ... be the prime factorization of n. Sequence gives k such that the sum of the numbers of 1's in the binary expansions of e_1, e_2, e_3, ... is odd.at n=59A000028
- Mersenne exponents: primes p such that 2^p - 1 is prime. Then 2^p - 1 is called a Mersenne prime.at n=11A000043
- Primes that divide at least one term in every Fibonacci sequence.at n=8A000057
- Numbers k such that (2k)^4 + 1 is prime.at n=36A000059
- Odious numbers: numbers with an odd number of 1's in their binary expansion.at n=63A000069
- Record gaps between primes (upper end) (compare A002386, which gives lower ends of these gaps).at n=5A000101
- a(n) = number of compositions of n in which the maximum part size is 4.at n=10A000102
- a(n) = sigma(n), the sum of the divisors of n. Also called sigma_1(n).at n=63A000203
- a(n) = 2^n - 1. (Sometimes called Mersenne numbers, although that name is usually reserved for A001348.)at n=7A000225
- 3*n - 2*floor(sqrt(4*n+5)) + 5.at n=50A000277
- Number of partitions into non-integral powers.at n=7A000327
- Primes and squares of primes.at n=35A000430
- n written in base where place values are positive cubes.at n=50A000433
- Number of nonnegative solutions of x^2 + y^2 = z in first n shells.at n=59A000592
- Number of nonnegative solutions to x^2 + y^2 + z^2 <= n.at n=29A000606
- Mersenne primes (primes of the form 2^n - 1).at n=3A000668
- Number of boron trees with n nodes, i.e. n-node rooted trees with degree <= 3 at root and out-degree <= 2 elsewhere.at n=9A000671
- Number of bicentered 3-valent (or boron, or binary) trees with n nodes.at n=13A000673
- Number of centered trees with n nodes.at n=11A000676
- Numbers k such that (1,k) is "good".at n=6A000696