9995
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12000
- Proper Divisor Sum (Aliquot Sum)
- 2005
- 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
- 7992
- Möbius Function
- 1
- Radical
- 9995
- 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
- 65
- 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
- Expansion of 1/((1-5x)(1-6x)(1-8x)(1-12x)).at n=3A028173
- Number of partitions of n into parts not of form 4k+2, 20k, 20k+9 or 20k-9. Also number of partitions in which no odd part is repeated, with at most 4 parts of size less than or equal to 2 and where differences between parts at distance 4 are greater than 1 when the smallest part is odd and greater than 2 when the smallest part is even.at n=48A036028
- Numbers having three 9's in base 10.at n=32A043527
- Numbers whose base-5 representation contains exactly two 0's and three 4's.at n=29A045213
- Numbers m such that m^2 can be obtained from m by inserting an internal block of (contiguous) digits.at n=18A045953
- Numbers k such that k^2 can be obtained from k by inserting a block of digits.at n=25A046838
- a(n) is the largest number which can be formed with no zeros, using least number of digits and having digit sum = n.at n=31A061219
- Smallest multiple of 5 with digit sum n.at n=31A069534
- Numbers k such that N*2^k + 1 is prime where N = 9999999999999999999999988888888888888888887777777777777777766666666666665555555555544444443333322211.at n=17A098467
- Near-repdigit semiprimes with 9 as repeated digit.at n=26A105990
- a(n) is constructed by concatenation of the "next" d(e) digits of e=exp(1), where d()=2, 7, 1, 8 are the digits of e.at n=10A106536
- Number of partitions of n with more even parts than odd parts.at n=40A108949
- Composite numbers between largest n-digit prime and the smallest (n+1) digit prime.at n=38A109936
- Numbers k such that k concatenated with k-7 gives the product of two numbers which differ by 8.at n=8A116113
- Numbers k such that k concatenated with itself gives the product of two numbers which differ by 6.at n=9A116159
- n times n+7 gives the concatenation of two numbers m and m-6.at n=9A116250
- Numbers k such that k * (k+6) is the concatenation of a number m with itself.at n=9A116290
- a(n) = prime(n)*prime(n+1) + prime(n) + prime(n+1).at n=24A126199
- Composite numbers, not ending with 0, sharing a 3-digit sequence with some of its prime factors.at n=2A131523
- Numbers k such that k and k^2 use only the digits 0, 1, 2, 5 and 9.at n=43A136826