172
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
- 6
- Divisor Sum
- 308
- Proper Divisor Sum (Aliquot Sum)
- 136
- 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
- 84
- Möbius Function
- 0
- Radical
- 86
- Omega Function (Ω)
- 3
- 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
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
- einshundertzweiundsiebzig· ordinal: einshundertzweiundsiebzigste
- English
- one hundred seventy-two· ordinal: one hundred seventy-second
- Spanish
- ciento setenta y dos· ordinal: 172º
- French
- cent soixante-douze· ordinal: cent soixante-douzième
- Italian
- centosettantadue· ordinal: 172º
- Latin
- centum septuaginta duo· ordinal: 172.
- Portuguese
- cento e setenta e dois· ordinal: 172º
Appears in sequences
- a(n) is the number of distinct (infinite) output sequences from binary n-stage shift register which feeds back the complement of the last stage.at n=12A000016
- a(n) = floor(n^(3/2)).at n=31A000093
- Central polygonal numbers (the Lazy Caterer's sequence): n(n+1)/2 + 1; or, maximal number of pieces formed when slicing a pancake with n cuts.at n=18A000124
- Positive zeros of Bessel function of order 0 rounded to nearest integer.at n=54A000134
- Number of n-step self-avoiding walks on cubic lattice ending at point with x=0.at n=4A000759
- Total number of 1's in binary expansions of 0, ..., n.at n=59A000788
- Numbers that are the sum of 2 successive primes.at n=22A001043
- Numbers m such that Sum_{k=0..m-1} exp(2*Pi*i*k^3/m) != 0.at n=47A001074
- a(n) = solution to the postage stamp problem with 3 denominations and n stamps.at n=10A001208
- Number of graphs with n nodes and n-4 edges.at n=10A001432
- Numbers whose digits contain no loops (version 2).at n=51A001742
- Primes multiplied by 4.at n=13A001749
- a(n) = floor((n+1/2)*(2+sqrt(2))); winning positions in the 2-Wythoff game.at n=50A001954
- Beatty sequence of (5+sqrt(13))/2.at n=39A001956
- A Beatty sequence: floor(n * (sqrt(5) + 3)).at n=32A001962
- Sum of totient function: a(n) = Sum_{k=1..n} phi(k), cf. A000010.at n=23A002088
- Numbers k for which the rank of the elliptic curve y^2 = x^3 - k*x is 0.at n=58A002156
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k*x is 0.at n=77A002158
- Values taken by totient function phi(m) (A000010).at n=62A002202
- Numbers k such that 15*2^k - 1 is prime.at n=16A002237