638844663167 has 2 divisors, whose sum is σ = 638844663168. Its totient is φ = 638844663166.

The previous prime is 638844663103. The next prime is 638844663181. The reversal of 638844663167 is 761366448836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638844663167 - 2⁶ = 638844663103 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638844663967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319422331583 + 319422331584.

It is an arithmetic number, because the mean of its divisors is an integer number (319422331584).

Almost surely, 2^638844663167 is an apocalyptic number.

638844663167 is a deficient number, since it is larger than the sum of its proper divisors (1).

638844663167 is an equidigital number, since it uses as much as digits as its factorization.

638844663167 is an evil number, because the sum of its binary digits is even.

The product of its digits is 83607552, while the sum is 62.

The spelling of 638844663167 in words is "six hundred thirty-eight billion, eight hundred forty-four million, six hundred sixty-three thousand, one hundred sixty-seven".