638772588833767 has 4 divisors (see below), whose sum is σ = 647522898269920. Its totient is φ = 630022279397616.

The previous prime is 638772588833719. The next prime is 638772588833779. The reversal of 638772588833767 is 767338885277836.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638772588833767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638772588833707) 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, 4375154717967 + ... + 4375154718112.

It is an arithmetic number, because the mean of its divisors is an integer number (161880724567480).

Almost surely, 2^{638772588833767} is an apocalyptic number.

638772588833767 is a deficient number, since it is larger than the sum of its proper divisors (8750309436153).

638772588833767 is an equidigital number, since it uses as much as digits as its factorization.

638772588833767 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8750309436152.

The product of its digits is 95591301120, while the sum is 88.

The spelling of 638772588833767 in words is "six hundred thirty-eight trillion, seven hundred seventy-two billion, five hundred eighty-eight million, eight hundred thirty-three thousand, seven hundred sixty-seven".