638636201656 has 16 divisors (see below), whose sum is σ = 1203460182000. Its totient is φ = 317713486464.

The previous prime is 638636201617. The next prime is 638636201657. The reversal of 638636201656 is 656102636836.

638636201656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638636201657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200575105 + ... + 200578288.

It is an arithmetic number, because the mean of its divisors is an integer number (75216261375).

Almost surely, 2^638636201656 is an apocalyptic number.

It is an amenable number.

638636201656 is a deficient number, since it is larger than the sum of its proper divisors (564823980344).

638636201656 is a wasteful number, since it uses less digits than its factorization.

638636201656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401153598 (or 401153594 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 52.

The spelling of 638636201656 in words is "six hundred thirty-eight billion, six hundred thirty-six million, two hundred one thousand, six hundred fifty-six".