638407402744 has 32 divisors (see below), whose sum is σ = 1268905603680. Its totient is φ = 300076401664.

The previous prime is 638407402681. The next prime is 638407402753. The reversal of 638407402744 is 447204704836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2622172 + ... + 2855275.

It is an arithmetic number, because the mean of its divisors is an integer number (39653300115).

Almost surely, 2^638407402744 is an apocalyptic number.

It is an amenable number.

638407402744 is a deficient number, since it is larger than the sum of its proper divisors (630498200936).

638407402744 is a wasteful number, since it uses less digits than its factorization.

638407402744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5478327 (or 5478323 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 49.

The spelling of 638407402744 in words is "six hundred thirty-eight billion, four hundred seven million, four hundred two thousand, seven hundred forty-four".