638585616 has 160 divisors (see below), whose sum is σ = 1819312128. Its totient is φ = 192360960.

The previous prime is 638585587. The next prime is 638585617. The reversal of 638585616 is 616585836.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (638585617) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1608330 + ... + 1608726.

Almost surely, 2^638585616 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 638585616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909656064).

638585616 is an abundant number, since it is smaller than the sum of its proper divisors (1180726512).

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

638585616 is a wasteful number, since it uses less digits than its factorization.

638585616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509 (or 503 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 48.

The square root of 638585616 is about 25270.2516014384. The cubic root of 638585616 is about 861.1385748756.

The spelling of 638585616 in words is "six hundred thirty-eight million, five hundred eighty-five thousand, six hundred sixteen".