638442459768959 has 4 divisors (see below), whose sum is σ = 638443281178680. Its totient is φ = 638441638359240.

The previous prime is 638442459768931. The next prime is 638442459768973. The reversal of 638442459768959 is 959867954244836.

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 638442459768959 - 2³² = 638438164801663 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 (638442459768359) 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, 409537877 + ... + 411093854.

It is an arithmetic number, because the mean of its divisors is an integer number (159610820294670).

Almost surely, 2^{638442459768959} is an apocalyptic number.

638442459768959 is a deficient number, since it is larger than the sum of its proper divisors (821409721).

638442459768959 is an equidigital number, since it uses as much as digits as its factorization.

638442459768959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821409720.

The product of its digits is 112870195200, while the sum is 89.

The spelling of 638442459768959 in words is "six hundred thirty-eight trillion, four hundred forty-two billion, four hundred fifty-nine million, seven hundred sixty-eight thousand, nine hundred fifty-nine".