10121
domain: N
Properties
Digital Properties
- Digit Count
- 5
- 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
- 10500
- Proper Divisor Sum (Aliquot Sum)
- 379
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9744
- Möbius Function
- 1
- Radical
- 10121
- 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
- 179
- 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
- Primes in ternary.at n=24A001363
- Expansion of 1/(1-x^3-x^4-x^5-x^6).at n=33A017819
- Denominators of continued fraction convergents to sqrt(30).at n=6A041049
- Denominators of continued fraction convergents to sqrt(120).at n=6A041219
- Numbers whose base-10 representation has exactly 5 runs.at n=10A043641
- a(n) * a(n)_reversed is a palindrome (and a(n) is not palindromic).at n=36A048344
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n-1 <= 2^(p+1), with a(1) = 1, a(2) = 3, and a(3) = 4.at n=13A049978
- Coefficients of monic irreducible polynomials over GF(3) listed in lexicographic order.at n=18A058944
- Coefficients of monic irreducible polynomials over GF(4) listed in lexicographic order.at n=30A058948
- a(n) = A061086(n) / n.at n=10A061087
- Numbers n such that sum of digits = number of digits.at n=36A061384
- Coefficients of irreducible polynomials over GF(3) listed in lexicographic order.at n=21A065020
- a(n) is the smallest index m such that Sum_{k=2..m} 1/PrimePi(k) >= n, where PrimePi()=A000720().at n=37A074633
- Another lazy binary representation of n: similar to A089591 except that the single carry is performed before the increment instead of after.at n=25A089600
- Number of partitions of n in which no parts are multiples of 25.at n=33A092885
- a(n) = 97 written in base n.at n=2A095586
- a(n) = 97 written in base 13 - n.at n=10A095587
- Number of partitions where no part is a multiple of 9.at n=34A104502
- 7th diagonal of triangle in A059317.at n=12A106173
- Expansion of g.f. -x*(5*x^7-20*x^6-2*x^5+54*x^4+7*x^3-20*x^2-8*x-1)/((x^4-x^3-3*x^2+x+1)*(x^4+x^3-3*x^2-x+1)).at n=10A122013