231281328 has 160 divisors (see below), whose sum is σ = 671956992. Its totient is φ = 68198400.

The previous prime is 231281299. The next prime is 231281329. The reversal of 231281328 is 823182132.

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

It is a junction number, because it is equal to n+sod(n) for n = 231281295 and 231281304.

It is not an unprimeable number, because it can be changed into a prime (231281329) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1037025 + ... + 1037247.

Almost surely, 2^231281328 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 231281328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335978496).

231281328 is an abundant number, since it is smaller than the sum of its proper divisors (440675664).

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

231281328 is a wasteful number, since it uses less digits than its factorization.

231281328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 317 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 231281328 is about 15207.9363491566. The cubic root of 231281328 is about 613.8282295274.

The spelling of 231281328 in words is "two hundred thirty-one million, two hundred eighty-one thousand, three hundred twenty-eight".