7915
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9504
- Proper Divisor Sum (Aliquot Sum)
- 1589
- 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
- 6328
- Möbius Function
- 1
- Radical
- 7915
- 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
- yes
- 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
- Digit sum of 'odd' number equals digit sum of 'sum' and 'juxtaposition' of its prime factors (counted with multiplicity).at n=38A036927
- Numbers whose base-4 representation contains exactly three 2's and three 3's.at n=33A045151
- Number of lambda calculus terms of size n, where size(lambda x.M) = 2 + size(M), size(M N) = 2 + size(M) + size(N), and size(V) = 1 + i for a variable V bound by the i-th enclosing lambda (corresponding to a binary encoding).at n=20A114851
- Semiprimes which are divisible by their multiplicative digital root.at n=47A118696
- a(n) = 4*n^2 + 12*n + 3.at n=42A153169
- Number of ways to partition n into distinct reduced fractions i/j with j <= n.at n=5A154887
- Composite numbers such that exactly ten distinct permutations of digits are prime.at n=21A163562
- Integers k whose binary expansion (D digits in length) is the same as the initial D digits of the binary expansion of the square root of k to the right of the binary point.at n=8A165309
- Gromov-Witten invariants for genus 3.at n=4A171111
- a(n) is the Severi degree for curves of degree n and cogenus 3.at n=4A171113
- Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined below in Comments.at n=18A192758
- Number of nX5 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically.at n=2A207085
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically.at n=23A207088
- Number of 3 X n 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically.at n=4A207089
- Number of nX5 0..1 arrays avoiding 0 0 0 horizontally and 0 1 0 vertically.at n=2A207179
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 horizontally and 0 1 0 vertically.at n=23A207182
- Smallest k such that k^2 is a concatenation of two numbers x and y where y = x + n^2 and x and y have the same number of digits.at n=30A236383
- Numbers that end in (..., 175, 175, 175, ...) under the rule: next term = product of the last four digits in the sequence so far.at n=44A239721
- Partial sums of A253086.at n=42A255150
- Start of first run of length n in Golomb's sequence A001462.at n=41A262986