231520128 has 64 divisors (see below), whose sum is σ = 702837120. Its totient is φ = 66147840.

The previous prime is 231520097. The next prime is 231520129. The reversal of 231520128 is 821025132.

231520128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 231520098 and 231520107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231520129) 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, 40378 + ... + 45753.

It is an arithmetic number, because the mean of its divisors is an integer number (10981830).

Almost surely, 2^231520128 is an apocalyptic number.

231520128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

231520128 is an abundant number, since it is smaller than the sum of its proper divisors (471316992).

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

231520128 is an equidigital number, since it uses as much as digits as its factorization.

231520128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86155 (or 86143 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 231520128 is about 15215.7854874469. The cubic root of 231520128 is about 614.0394178699.

The spelling of 231520128 in words is "two hundred thirty-one million, five hundred twenty thousand, one hundred twenty-eight".