638657218883 has 4 divisors (see below), whose sum is σ = 676225290600. Its totient is φ = 601089147168.

The previous prime is 638657218867. The next prime is 638657218919. The reversal of 638657218883 is 388812756836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638657218883 - 2⁴ = 638657218867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638657218483) 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, 18784035833 + ... + 18784035866.

It is an arithmetic number, because the mean of its divisors is an integer number (169056322650).

Almost surely, 2^638657218883 is an apocalyptic number.

638657218883 is a deficient number, since it is larger than the sum of its proper divisors (37568071717).

638657218883 is a wasteful number, since it uses less digits than its factorization.

638657218883 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37568071716.

The product of its digits is 92897280, while the sum is 65.

The spelling of 638657218883 in words is "six hundred thirty-eight billion, six hundred fifty-seven million, two hundred eighteen thousand, eight hundred eighty-three".