638636550507 has 12 divisors (see below), whose sum is σ = 947406775120. Its totient is φ = 414250735248.

The previous prime is 638636550491. The next prime is 638636550527. The reversal of 638636550507 is 705055636836.

638636550507 is a `hidden beast` number, since 6 + 3 + 8 + 6 + 36 + 550 + 50 + 7 = 666.

638636550507 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 638636550507 - 2⁴ = 638636550491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638636550527) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 958913407 + ... + 958914072.

Almost surely, 2^638636550507 is an apocalyptic number.

638636550507 is a deficient number, since it is larger than the sum of its proper divisors (308770224613).

638636550507 is a wasteful number, since it uses less digits than its factorization.

638636550507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1917827522 (or 1917827519 counting only the distinct ones).

The product of its (nonzero) digits is 13608000, while the sum is 54.

The spelling of 638636550507 in words is "six hundred thirty-eight billion, six hundred thirty-six million, five hundred fifty thousand, five hundred seven".