231431328 has 72 divisors (see below), whose sum is σ = 665601300. Its totient is φ = 76268544.

The previous prime is 231431311. The next prime is 231431329. The reversal of 231431328 is 823134132.

231431328 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 221771664 + 9659664 = 14892^2 + 3108^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (231431329) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21118 + ... + 30146.

Almost surely, 2^231431328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231431328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332800650).

231431328 is an abundant number, since it is smaller than the sum of its proper divisors (434169972).

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

231431328 is a wasteful number, since it uses less digits than its factorization.

231431328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9134 (or 9123 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 231431328 is about 15212.8671853796. The cubic root of 231431328 is about 613.9609024891.

The spelling of 231431328 in words is "two hundred thirty-one million, four hundred thirty-one thousand, three hundred twenty-eight".