638788911 has 8 divisors (see below), whose sum is σ = 896545920. Its totient is φ = 403445592.

The previous prime is 638788907. The next prime is 638788933. The reversal of 638788911 is 119887836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638788911 - 2² = 638788907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638788901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5603355 + ... + 5603468.

It is an arithmetic number, because the mean of its divisors is an integer number (112068240).

Almost surely, 2^638788911 is an apocalyptic number.

638788911 is a deficient number, since it is larger than the sum of its proper divisors (257757009).

638788911 is a wasteful number, since it uses less digits than its factorization.

638788911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11206845.

The product of its digits is 580608, while the sum is 51.

The square root of 638788911 is about 25274.2736987633. The cubic root of 638788911 is about 861.2299469057.

The spelling of 638788911 in words is "six hundred thirty-eight million, seven hundred eighty-eight thousand, nine hundred eleven".