12813
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17088
- Proper Divisor Sum (Aliquot Sum)
- 4275
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8540
- Möbius Function
- 1
- Radical
- 12813
- 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
- 63
- 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
- Decimal part of cube root of a(n) starts with 4: first term of runs.at n=22A034130
- Numbers n such that 54 'Reverse and Add' steps are needed to reach a palindrome.at n=2A065321
- Trajectory of 77 under the Reverse and Add! operation carried out in base 2.at n=12A075253
- Number of ways to partition the sum of all divisors of n (sigma(n), A000203) into distinct positive integers not greater than n.at n=31A079125
- Leading coefficients of self-interpolating polynomials from A103423.at n=5A103417
- Polynomials interpolating their own integral coefficients, read by row. The leading coefficients are positive and minimal.at n=15A103423
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 1), (0, 1), (1, 0), (1, 1)}.at n=8A151441
- a(n) = 12*n^2 - 8*n + 9.at n=32A167585
- a(n) = 6*a(n-1)-8*a(n-2)-9 for n > 2; a(0) = 77, a(1) = 897, a(2) = 3333.at n=3A176632
- Total number of positive integers below 10^n requiring 7 positive biquadrates in their representation as sum of biquadrates.at n=4A186659
- Positive integers m with 2^(m-1)*phi(m) - 1 prime, where phi(.) is Euler's totient function.at n=27A236375
- a(n) = 27*n^2/2 + 45*n/2 - 12 (n>=1).at n=29A304375
- a(n) = Sum_{k=1..n-1} k^2*phi(k) + n^2*phi(n)/2, where phi = A000010.at n=15A333293
- a(1) = 1; a(n+1) = n + Sum_{d|n} a(d).at n=53A345140
- Number of partitions of n into 10 or more parts.at n=27A347547