638328945 has 16 divisors (see below), whose sum is σ = 1021954752. Its totient is φ = 340232640.

The previous prime is 638328923. The next prime is 638328983. The reversal of 638328945 is 549823836.

It is not a de Polignac number, because 638328945 - 2⁶ = 638328881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 638328894 and 638328903.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13894 + ... + 38336.

It is an arithmetic number, because the mean of its divisors is an integer number (63872172).

Almost surely, 2^638328945 is an apocalyptic number.

It is an amenable number.

638328945 is a deficient number, since it is larger than the sum of its proper divisors (383625807).

638328945 is a wasteful number, since it uses less digits than its factorization.

638328945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26192.

The product of its digits is 1244160, while the sum is 48.

The square root of 638328945 is about 25265.1725701607. The cubic root of 638328945 is about 861.0231850132.

The spelling of 638328945 in words is "six hundred thirty-eight million, three hundred twenty-eight thousand, nine hundred forty-five".