901
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
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 972
- Proper Divisor Sum (Aliquot Sum)
- 71
- 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
- 832
- Möbius Function
- 1
- Radical
- 901
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 54
- 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
- neunhunderteins· ordinal: neunhunderteinsste
- English
- nine hundred one· ordinal: nine hundred first
- Spanish
- novecientos uno· ordinal: 901º
- French
- neuf cent un· ordinal: neuf cent unième
- Italian
- novecentouno· ordinal: 901º
- Latin
- nongenti unus· ordinal: 901.
- Portuguese
- novecentos e um· ordinal: 901º
Appears in sequences
- Number of positive integers <= 2^n of form x^2 + 4 y^2.at n=12A000072
- a(n) = floor(n^2/3).at n=52A000212
- Number of points of norm <= n^2 in square lattice.at n=17A000328
- Numbers beginning with letter 'n' in English.at n=13A000981
- Generalized octagonal numbers: k*(3*k-2), k=0, +- 1, +- 2, +-3, ...at n=34A001082
- Triangular numbers plus quarter-squares: n*(n+1)/2 + floor((n+1)^2/4) (i.e., A000217(n) + A002620(n+1)).at n=34A001859
- a(n) = n^2 + 1.at n=30A002522
- Numbers that are the sum of 12 positive 7th powers.at n=7A003379
- Roman numerals with 1 letter, in alphabetical order; then those with 2 letters, etc.at n=53A003588
- Primes written backwards.at n=28A004087
- Odd numbers written backwards.at n=54A004156
- a(n) = ceiling(n*phi^7), where phi is the golden ratio, A001622.at n=31A004962
- a(n)=least number m such that m-a(n-1)<>a(j)-a(k) for all j,k less than m; a(1)=1, a(2)=3.at n=29A004979
- Centered triangular numbers: a(n) = 3*n*(n-1)/2 + 1.at n=24A005448
- Number of fractions in Farey series of order n.at n=54A005728
- Coefficients of period polynomials.at n=14A006309
- Coordination sequence T1 for Zeolite Code CHA.at n=23A008066
- Coordination sequence T2 for Zeolite Code LTN.at n=21A008141
- Composite but smallest prime factor >= 17.at n=23A008367
- Numbers that do not contain the letter 't'.at n=49A008523