8575
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 12400
- Proper Divisor Sum (Aliquot Sum)
- 3825
- 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
- 5880
- Möbius Function
- 0
- Radical
- 35
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 127
- 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
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers of the form 5^i*7^j with i, j >= 0.at n=18A003595
- tan(exp(x)-cos(x)) = x + 2/2!*x^2 + 3/3!*x^3 + 24/4!*x^4 + 157/5!*x^5...at n=7A013312
- Number of subsets of { 1, ..., n } containing an A.P. of length 8.at n=18A018793
- Numbers k such that 165*2^k+1 is prime.at n=48A032459
- a(n) = 7*n^2.at n=35A033582
- Numbers whose prime factors are 5 and 7.at n=8A033851
- Composite numbers whose prime factors contain no digits other than 5 and 7.at n=21A036320
- Numbers whose prime factors are in {5, 7, 11}.at n=36A036490
- Numbers whose base-5 representation contains exactly two 0's and three 3's.at n=25A045198
- a(1)=9; if n = Product p_i^e_i, n > 1, then a(n) = Product p_{i+2}^{e_i+1}.at n=17A045972
- Odd numbers with exactly 5 palindromic prime factors (counted with multiplicity).at n=32A046375
- Solutions to sigma(x)+2=sigma(x+2) other than the smaller of twin primes.at n=1A050507
- Generalized Stirling number triangle of first kind.at n=25A051186
- Numbers n such that n | 9^n + 8^n + 7^n + 6^n + 5^n.at n=20A057253
- Numbers k that divide 8^k + 7^k + 6^k + 5^k + 4^k + 3^k + 2^k.at n=27A057490
- Numbers k such that the sum over the prime divisors of k equals the number of divisors of k.at n=33A069234
- Largest proper divisor of n^3.at n=33A071378
- The terms of A055258 (sums of two powers of 7) divided by 2.at n=18A073218
- Smallest k such that trinomial x^A001153(n) + x^k + 1 over GF(2) is primitive.at n=17A074743
- Numbers n such that repunit(n) concatenated with its 10's complement is prime; or numbers n such that (1+7*10^n+100^n)/9 is prime.at n=10A108966