638353665755 has 16 divisors (see below), whose sum is σ = 826084144704. Its totient is φ = 470751177600.

The previous prime is 638353665731. The next prime is 638353665769. The reversal of 638353665755 is 557566353836.

It is not a de Polignac number, because 638353665755 - 2²⁶ = 638286556891 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6707096 + ... + 6801605.

It is an arithmetic number, because the mean of its divisors is an integer number (51630259044).

Almost surely, 2^638353665755 is an apocalyptic number.

638353665755 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

638353665755 is a deficient number, since it is larger than the sum of its proper divisors (187730478949).

638353665755 is a wasteful number, since it uses less digits than its factorization.

638353665755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13509446.

The product of its digits is 204120000, while the sum is 62.

The spelling of 638353665755 in words is "six hundred thirty-eight billion, three hundred fifty-three million, six hundred sixty-five thousand, seven hundred fifty-five".