331720628 has 12 divisors (see below), whose sum is σ = 605750880. Its totient is φ = 158648952.

The previous prime is 331720607. The next prime is 331720633. The reversal of 331720628 is 826027133.

It is a happy number.

It is a super-2 number, since 2×331720628² = 220077150081428768, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 331720594 and 331720603.

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, 1802738 + ... + 1802921.

It is an arithmetic number, because the mean of its divisors is an integer number (50479240).

Almost surely, 2^331720628 is an apocalyptic number.

It is an amenable number.

331720628 is a deficient number, since it is larger than the sum of its proper divisors (274030252).

331720628 is a wasteful number, since it uses less digits than its factorization.

331720628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3605686 (or 3605684 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 331720628 is about 18213.1992796433. The cubic root of 331720628 is about 692.2412787560.

The spelling of 331720628 in words is "three hundred thirty-one million, seven hundred twenty thousand, six hundred twenty-eight".