638865362576 has 80 divisors (see below), whose sum is σ = 1444449216000. Its totient is φ = 273619487232.

The previous prime is 638865362549. The next prime is 638865362593. The reversal of 638865362576 is 675263568836.

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, 8485385 + ... + 8560343.

It is an arithmetic number, because the mean of its divisors is an integer number (18055615200).

Almost surely, 2^638865362576 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 638865362576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722224608000).

638865362576 is an abundant number, since it is smaller than the sum of its proper divisors (805583853424).

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

638865362576 is a wasteful number, since it uses less digits than its factorization.

638865362576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76541 (or 76521 counting only the distinct ones).

The product of its digits is 261273600, while the sum is 65.

The spelling of 638865362576 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, three hundred sixty-two thousand, five hundred seventy-six".