8722
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 15390
- Proper Divisor Sum (Aliquot Sum)
- 6668
- 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
- 3696
- Möbius Function
- 0
- Radical
- 1246
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 140
- Smith Number
- no
- Vampire 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
Appears in sequences
- a(n) = (11*n+1)*(11*n+10).at n=8A001536
- Numbers whose set of base-16 digits is {1,2}.at n=27A032936
- Convolution of Catalan numbers A000108(n+1), n >= 0, with A020918.at n=4A041005
- a(n) = Sum_{i=0..n} T(i,n-i) where T is A049627.at n=43A049628
- Partial sums of the partition function (A000041), with the last term subtracted. Also the sum of the row of the character table for S_n corresponding to the partition n-1,1 for n>1. Also the sum over all partitions lambda of n of one less than the number of 1's in lambda.at n=27A058884
- When expressed in base 4 and then interpreted in base 6, is a multiple of the original number.at n=20A062921
- Nonsquares which are the product of two numbers with the same digits (leading zeros are forbidden).at n=35A072443
- Determinant of M(n), the n X n matrix defined by m(i,i) = 1, m(i,j) = i-j.at n=18A079034
- Triangle read by rows in which row n gives coefficients of polynomial R_n(y) that satisfies R_n(1/2) = 4^n, where R_n(y) forms the initial (n+1) terms of g.f. A077860(y)^(n+1).at n=25A097179
- Expansion of (1+x-2*x^2)/(1-21*x^2-7*x^3).at n=6A121458
- a(n) = prime(n)*(prime(n+1) + 1).at n=23A123134
- Numbers which are the product of a non-palindrome and its reversal, where leading zeros are not allowed.at n=35A129623
- Product of n-th prime and n-th prime written backwards.at n=23A133019
- Product of n-th Fibonacci number and n-th Fibonacci number written backwards.at n=11A133022
- Let f(m) = number of steps needed to reach a Harshad number when the map k->A062028(l) is iterated starting at m; a(n) = smallest m such that f(m) = n.at n=69A181664
- Total Wiener index of double-star trees with n nodes.at n=22A186235
- Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).at n=7A234260
- T(n,k) is the number of (n+1) X (k+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).at n=37A234266
- T(n,k) is the number of (n+1) X (k+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).at n=43A234266
- Number of isosceles triangles, distinct up to congruence, on a centered hexagonal grid of size n.at n=39A241237