231625728 has 132 divisors (see below), whose sum is σ = 686244468. Its totient is φ = 75202560.

The previous prime is 231625699. The next prime is 231625733. The reversal of 231625728 is 827526132.

231625728 is a `hidden beast` number, since 2 + 3 + 1 + 625 + 7 + 28 = 666.

231625728 is digitally balanced in base 3, 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 4460544 + 227165184 = 2112^2 + 15072^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 231625692 and 231625701.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 377550 + ... + 378162.

Almost surely, 2^231625728 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 231625728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343122234).

231625728 is an abundant number, since it is smaller than the sum of its proper divisors (454618740).

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

231625728 is a wasteful number, since it uses less digits than its factorization.

231625728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680 (or 659 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 231625728 is about 15219.2551723138. The cubic root of 231625728 is about 614.1327613833.

The spelling of 231625728 in words is "two hundred thirty-one million, six hundred twenty-five thousand, seven hundred twenty-eight".