231388220 has 24 divisors (see below), whose sum is σ = 555332064. Its totient is φ = 79333056.

The previous prime is 231388181. The next prime is 231388229. The reversal of 231388220 is 22883132.

231388220 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231388229) 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, 826247 + ... + 826526.

It is an arithmetic number, because the mean of its divisors is an integer number (23138836).

Almost surely, 2^231388220 is an apocalyptic number.

231388220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231388220 is an abundant number, since it is smaller than the sum of its proper divisors (323943844).

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

231388220 is a wasteful number, since it uses less digits than its factorization.

231388220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1652789 (or 1652787 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 231388220 is about 15211.4502924606. The cubic root of 231388220 is about 613.9227799205.

The spelling of 231388220 in words is "two hundred thirty-one million, three hundred eighty-eight thousand, two hundred twenty".