7965
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 14400
- Proper Divisor Sum (Aliquot Sum)
- 6435
- 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
- 4176
- Möbius Function
- 0
- Radical
- 885
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 52
- 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
- no
- Odd
- yes
Appears in sequences
- 10-gonal (or decagonal) numbers: a(n) = n*(4*n-3).at n=45A001107
- Number of deterministic, completely-defined, initially-connected finite automata with 3 inputs and n unlabeled states.at n=2A006690
- Number of partitions of n into parts of sizes {a( )} is a(n).at n=51A007209
- arcsin(tan(arctanh(x)))=x+5/3!*x^3+129/5!*x^5+7965/7!*x^7+910785/9!*x^9...at n=3A012176
- Odd 10-gonal (or decagonal) numbers.at n=22A028993
- Numbers whose base-5 representation contains exactly two 2's and three 3's.at n=34A045273
- Maximal elements of pairs of "Super Unitary Amicable Numbers", sorted by their minimal elements.at n=25A045614
- Starting index of a string of 4 or more consecutive equal digits in decimal expansion of Pi.at n=9A049516
- Starting index of a string of exactly 4 consecutive equal digits in decimal expansion of Pi.at n=6A049520
- Number of winning length n strings with a 5-symbol alphabet in "same game".at n=8A065238
- Numbers k such that phi(sigma(k)) + sigma(phi(k)) = 2k.at n=9A066950
- Numbers k such that phi((prime(k)-1)/2) = sigma(k).at n=30A068474
- Numbers k such that gcd(k, reverse(k)) = 27 = 3^3, where reverse(x) = A004086(x).at n=27A072016
- Non-balanced numbers in A015765.at n=34A074868
- Friendly numbers (see A074902) such that sigma(n) is not friendly.at n=21A074873
- Duplicate of A006690.at n=2A082167
- Starting positions of strings of three 2's in the decimal expansion of Pi.at n=9A083606
- Matrix cube of triangle A107671.at n=3A107676
- 10-gonal numbers for which the sum of the digits is also a 10-gonal number.at n=8A119547
- 10-gonal numbers which are divisible by the sum of their digits.at n=17A119548