231117728 has 12 divisors (see below), whose sum is σ = 455013090. Its totient is φ = 115558848.

The previous prime is 231117707. The next prime is 231117751. The reversal of 231117728 is 827711132.

It can be written as a sum of positive squares in only one way, i.e., 181387024 + 49730704 = 13468^2 + 7052^2 .

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 7222429 = 231117728 / (2 + 3 + 1 + 1 + 1 + 7 + 7 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 231117694 and 231117703.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3611183 + ... + 3611246.

Almost surely, 2^231117728 is an apocalyptic number.

It is an amenable number.

231117728 is a deficient number, since it is larger than the sum of its proper divisors (223895362).

231117728 is an equidigital number, since it uses as much as digits as its factorization.

231117728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7222439 (or 7222431 counting only the distinct ones).

The product of its digits is 4704, while the sum is 32.

The square root of 231117728 is about 15202.5566270940. The cubic root of 231117728 is about 613.6834621325.

The spelling of 231117728 in words is "two hundred thirty-one million, one hundred seventeen thousand, seven hundred twenty-eight".