105999 has 8 divisors (see below), whose sum is σ = 143280. Its totient is φ = 69696.

The previous prime is 105997. The next prime is 106013. The reversal of 105999 is 999501.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 105999 - 2¹ = 105997 is a prime.

It is a super-2 number, since 2×105999² = 22471576002, which contains 22 as substring.

105999 is a modest number, since divided by 999 gives 105 as remainder.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69 + ... + 465.

It is an arithmetic number, because the mean of its divisors is an integer number (17910).

2¹⁰⁵⁹⁹⁹ is an apocalyptic number.

105999 is a deficient number, since it is larger than the sum of its proper divisors (37281).

105999 is an equidigital number, since it uses as much as digits as its factorization.

105999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489.

The product of its (nonzero) digits is 3645, while the sum is 33.

The square root of 105999 is about 325.5748761806. The cubic root of 105999 is about 47.3260860865.

The spelling of 105999 in words is "one hundred five thousand, nine hundred ninety-nine".