1121
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 5
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1200
- Proper Divisor Sum (Aliquot Sum)
- 79
- 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
- 1044
- Möbius Function
- 1
- Radical
- 1121
- 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
- 44
- Smith Number
- no
- Vampire 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
Appears in sequences
- Number of partitions into non-integral powers.at n=17A000327
- Generalized octagonal numbers: k*(3*k-2), k=0, +- 1, +- 2, +-3, ...at n=38A001082
- A continued fraction.at n=9A001112
- Smallest natural number requiring n words in English (as spoken in England).at n=6A001167
- Primes in ternary.at n=13A001363
- Number of letters in English name for n increases at these numbers.at n=22A001619
- Triangular numbers plus quarter-squares: n*(n+1)/2 + floor((n+1)^2/4) (i.e., A000217(n) + A002620(n+1)).at n=38A001859
- Class numbers of quadratic fields.at n=10A001985
- Class numbers of quadratic fields.at n=9A001985
- Class numbers of quadratic fields.at n=11A001985
- Numbers that are the sum of 5 positive 5th powers.at n=23A003350
- Primes written in base 4.at n=23A004678
- Fibonacci numbers written in base 4.at n=11A004687
- a(n) = (n + 3)*(n^2 + 6*n + 2)/6.at n=16A005286
- 1 + (sum of first n odd primes - n)/2.at n=34A005521
- Related to representations as sums of Fibonacci numbers.at n=22A006133
- Numbers in base 3.at n=43A007089
- Integers written in factorial base.at n=35A007623
- Describe the previous term! (method B - initial term is 1).at n=3A007651
- a(n) = n OR n^2 (applied to binary expansions).at n=32A007745