638655634444 has 6 divisors (see below), whose sum is σ = 1117647360284. Its totient is φ = 319327817220.

The previous prime is 638655634427. The next prime is 638655634457. The reversal of 638655634444 is 444436556836.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79831954302 + ... + 79831954309.

Almost surely, 2^638655634444 is an apocalyptic number.

It is an amenable number.

638655634444 is a deficient number, since it is larger than the sum of its proper divisors (478991725840).

638655634444 is a wasteful number, since it uses less digits than its factorization.

638655634444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159663908615 (or 159663908613 counting only the distinct ones).

The product of its digits is 99532800, while the sum is 58.

The spelling of 638655634444 in words is "six hundred thirty-eight billion, six hundred fifty-five million, six hundred thirty-four thousand, four hundred forty-four".