638856528 has 20 divisors (see below), whose sum is σ = 1650379488. Its totient is φ = 212952160.

The previous prime is 638856527. The next prime is 638856553. The reversal of 638856528 is 825658836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638856523) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6654708 + ... + 6654803.

Almost surely, 2^638856528 is an apocalyptic number.

It is an amenable number.

638856528 is an abundant number, since it is smaller than the sum of its proper divisors (1011522960).

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

638856528 is a wasteful number, since it uses less digits than its factorization.

638856528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13309522 (or 13309516 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 51.

The square root of 638856528 is about 25275.6113279185. The cubic root of 638856528 is about 861.2603334333.

The spelling of 638856528 in words is "six hundred thirty-eight million, eight hundred fifty-six thousand, five hundred twenty-eight".