7157
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7596
- Proper Divisor Sum (Aliquot Sum)
- 439
- 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
- 6720
- Möbius Function
- 1
- Radical
- 7157
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 101
- 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
- Representation degeneracies for boson strings.at n=27A005294
- Number of n-dimensional partitions of 5.at n=16A008779
- Expansion of x^2*(2 - x + x^2) / ((1 + x)*(1 - x)^4).at n=33A026035
- Sequence A037094 shown in octal.at n=5A037099
- Numbers whose base-5 representation contains exactly three 1's and three 2's.at n=13A045232
- Thickened pyramidal numbers: a(n) = 2*(n+1)*n + Sum_{i=1..n} (4*i*(i-1) + 1).at n=17A050533
- Numbers n such that 235*2^n-1 is prime.at n=14A050869
- Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome.at n=12A074303
- Smallest multiple of the n-th prime beginning and ending in n with a(1)=a(3)=0.at n=6A078212
- McKay-Thompson series of class 32a for the Monster group.at n=33A107635
- Semiprimes which are the sum of two pentagonal numbers (A000326) in exactly two different ways.at n=38A120536
- a(1)=1, a(n)=a(n-1)+n^0 if n odd, a(n)=a(n-1)+ n^2 if n is even.at n=33A135301
- The number of degree sequences with degree sum 2n representable by a connected graph (with multiple edges allowed).at n=15A147878
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (-1, 0, 1), (0, 1, -1), (1, -1, 1), (1, 1, 1)}.at n=7A149785
- Partial sums of A034897.at n=9A174226
- Partial sums of floor(Fibonacci(n)/4).at n=21A179006
- Number of ways to place 8 nonattacking wazirs on an n X n board.at n=4A201508
- Number of 2 X 2 matrices with all elements in {1,2,...,n} and determinant in {0,1}.at n=37A209992
- Conjectured record-breaking numbers of odd elements, for ascending positive integers k, in primitive cycles of positive integers under iteration by the Collatz-like 3x+k function.at n=26A226673
- Antiharmonic mean of the divisors of A228023(n) (the n-th primitive antiharmonic number).at n=41A228024