1231291328 has 28 divisors (see below), whose sum is σ = 2509384872. Its totient is φ = 599005440.

The previous prime is 1231291319. The next prime is 1231291331. The reversal of 1231291328 is 8231921321.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 1231291294 and 1231291303.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 257618 + ... + 262353.

Almost surely, 2^1231291328 is an apocalyptic number.

It is an amenable number.

1231291328 is an abundant number, since it is smaller than the sum of its proper divisors (1278093544).

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

1231291328 is an equidigital number, since it uses as much as digits as its factorization.

1231291328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520020 (or 520010 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 1231291328 is about 35089.7610137202. The cubic root of 1231291328 is about 1071.8160930525.

The spelling of 1231291328 in words is "one billion, two hundred thirty-one million, two hundred ninety-one thousand, three hundred twenty-eight".