231998091 has 16 divisors (see below), whose sum is σ = 333715200. Its totient is φ = 142515360.

The previous prime is 231998077. The next prime is 231998147. The reversal of 231998091 is 190899132.

It is not a de Polignac number, because 231998091 - 2¹⁷ = 231867019 is a prime.

It is a super-2 number, since 2×231998091² = 107646228455288562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (231998051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18396 + ... + 28326.

It is an arithmetic number, because the mean of its divisors is an integer number (20857200).

Almost surely, 2^231998091 is an apocalyptic number.

231998091 is a deficient number, since it is larger than the sum of its proper divisors (101717109).

231998091 is a wasteful number, since it uses less digits than its factorization.

231998091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10546.

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 231998091 is about 15231.4835456038. The cubic root of 231998091 is about 614.4616797725.

The spelling of 231998091 in words is "two hundred thirty-one million, nine hundred ninety-eight thousand, ninety-one".