638844847187 has 16 divisors (see below), whose sum is σ = 661150533120. Its totient is φ = 616822280928.

The previous prime is 638844847079. The next prime is 638844847211. The reversal of 638844847187 is 781748448836.

638844847187 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638844847187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638844847387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2454614 + ... + 2702372.

It is an arithmetic number, because the mean of its divisors is an integer number (41321908320).

Almost surely, 2^638844847187 is an apocalyptic number.

638844847187 is a deficient number, since it is larger than the sum of its proper divisors (22305685933).

638844847187 is a wasteful number, since it uses less digits than its factorization.

638844847187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248330.

The product of its digits is 231211008, while the sum is 68.

The spelling of 638844847187 in words is "six hundred thirty-eight billion, eight hundred forty-four million, eight hundred forty-seven thousand, one hundred eighty-seven".