638385516 has 96 divisors (see below), whose sum is σ = 1736017920. Its totient is φ = 202485888.

The previous prime is 638385481. The next prime is 638385529. The reversal of 638385516 is 615583836.

638385516 is a `hidden beast` number, since 63 + 8 + 38 + 551 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 578221 + ... + 579323.

It is an arithmetic number, because the mean of its divisors is an integer number (18083520).

Almost surely, 2^638385516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638385516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (868008960).

638385516 is an abundant number, since it is smaller than the sum of its proper divisors (1097632404).

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

638385516 is a wasteful number, since it uses less digits than its factorization.

638385516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1372 (or 1364 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 638385516 is about 25266.2920904513. The cubic root of 638385516 is about 861.0486199159.

The spelling of 638385516 in words is "six hundred thirty-eight million, three hundred eighty-five thousand, five hundred sixteen".