231999 has 8 divisors (see below), whose sum is σ = 327600. Its totient is φ = 145536.

The previous prime is 231967. The next prime is 232003. The reversal of 231999 is 999132.

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

It is not a de Polignac number, because 231999 - 2⁵ = 231967 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

231999 is a modest number, since divided by 999 gives 231 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2224 + ... + 2325.

It is an arithmetic number, because the mean of its divisors is an integer number (40950).

2²³¹⁹⁹⁹ is an apocalyptic number.

231999 is a deficient number, since it is larger than the sum of its proper divisors (95601).

231999 is a wasteful number, since it uses less digits than its factorization.

231999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4569.

The product of its digits is 4374, while the sum is 33.

The square root of 231999 is about 481.6627450821. The cubic root of 231999 is about 61.4462482286.

The spelling of 231999 in words is "two hundred thirty-one thousand, nine hundred ninety-nine".