7573
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
- 2
- Divisor Sum
- 7574
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 7572
- Möbius Function
- -1
- Radical
- 7573
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 39
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 961
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes of form k^2 + 4.at n=18A005473
- Number of connected trivalent graphs with 2n nodes and girth exactly 6.at n=12A006926
- a(n) = prime(n^2).at n=30A011757
- First occurrence of exactly n identical terms in A007448.at n=21A016046
- Numbers with exactly 7 1's in their ternary expansion.at n=18A023698
- a(n) = 3*a(n-1) + a(n-2) - a(n-3) for n >= 3, a(0)=1, a(1)=2, a(2)=7.at n=8A030186
- Smallest nontrivial extension of n-th palindromic prime which is a prime.at n=15A030680
- Number of matchings in graph P_{8} X P_{n}.at n=2A033511
- Sums of 7 distinct powers of 3.at n=10A038469
- Prime number spiral (clockwise, Northwest spoke).at n=15A053999
- Sum of a(n) terms of 1/k^(9/10) first exceeds n.at n=15A056186
- Primes p for which the period of reciprocal 1/p is (p-1)/12.at n=11A056217
- Primes p with the following property: let d_1, d_2, ... be the distinct digits occurring in the decimal expansion of p. Then for each d_i, dropping all the digits d_i from p produces a prime number. Leading 0's are not allowed.at n=36A057876
- Primes with 3 distinct digits that remain prime (no leading zeros allowed) after deleting all occurrences of any one of its distinct digits.at n=26A057879
- Primes p that have exactly two primitive roots that are not primitive roots mod p^2.at n=36A060518
- a(n)=A074639(A074647(n)).at n=32A074648
- Primes p such that 3p is equidistant from consecutive prime twin pairs.at n=42A074931
- Number of times that the numerator of a sum generated from the set 1, 1/2, 1/3,..., 1/n is prime.at n=13A075188
- Primes which can be expressed as a sum of distinct powers of 3.at n=40A077717
- a(n) = 4*(n+1)*n + 5.at n=43A078370