638403576845 has 16 divisors (see below), whose sum is σ = 806445768000. Its totient is φ = 483817961088.

The previous prime is 638403576817. The next prime is 638403576929. The reversal of 638403576845 is 548675304836.

It is a cyclic number.

It is not a de Polignac number, because 638403576845 - 2²⁴ = 638386799629 is a prime.

It is a congruent number.

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, 1815386 + ... + 2138324.

It is an arithmetic number, because the mean of its divisors is an integer number (50402860500).

Almost surely, 2^638403576845 is an apocalyptic number.

It is an amenable number.

638403576845 is a deficient number, since it is larger than the sum of its proper divisors (168042191155).

638403576845 is a wasteful number, since it uses less digits than its factorization.

638403576845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343772.

The product of its (nonzero) digits is 58060800, while the sum is 59.

The spelling of 638403576845 in words is "six hundred thirty-eight billion, four hundred three million, five hundred seventy-six thousand, eight hundred forty-five".