231991100 has 36 divisors (see below), whose sum is σ = 549188808. Its totient is φ = 84360000.

The previous prime is 231991099. The next prime is 231991157. The reversal of 231991100 is 1199132.

It is a self number, because there is not a number n which added to its sum of digits gives 231991100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104351 + ... + 106550.

Almost surely, 2^231991100 is an apocalyptic number.

231991100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231991100 is an abundant number, since it is smaller than the sum of its proper divisors (317197708).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231991100 is a wasteful number, since it uses less digits than its factorization.

231991100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210926 (or 210919 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 231991100 is about 15231.2540521127. The cubic root of 231991100 is about 614.4555076747.

The spelling of 231991100 in words is "two hundred thirty-one million, nine hundred ninety-one thousand, one hundred".