638650090761 has 32 divisors (see below), whose sum is σ = 887018815488. Its totient is φ = 408288928320.

The previous prime is 638650090753. The next prime is 638650090807. The reversal of 638650090761 is 167090056836.

It is not a de Polignac number, because 638650090761 - 2³ = 638650090753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638650090751) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5298976 + ... + 5418158.

It is an arithmetic number, because the mean of its divisors is an integer number (27719337984).

Almost surely, 2^638650090761 is an apocalyptic number.

It is an amenable number.

638650090761 is a deficient number, since it is larger than the sum of its proper divisors (248368724727).

638650090761 is a wasteful number, since it uses less digits than its factorization.

638650090761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119741.

The product of its (nonzero) digits is 1632960, while the sum is 51.

The spelling of 638650090761 in words is "six hundred thirty-eight billion, six hundred fifty million, ninety thousand, seven hundred sixty-one".