638865422 has 16 divisors (see below), whose sum is σ = 1065305472. Its totient is φ = 285348960.

The previous prime is 638865419. The next prime is 638865433. The reversal of 638865422 is 224568836.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395513 + ... + 397124.

It is an arithmetic number, because the mean of its divisors is an integer number (66581592).

Almost surely, 2^638865422 is an apocalyptic number.

638865422 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

638865422 is a deficient number, since it is larger than the sum of its proper divisors (426440050).

638865422 is a wasteful number, since it uses less digits than its factorization.

638865422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792683.

The product of its digits is 552960, while the sum is 44.

The square root of 638865422 is about 25275.7872676599. The cubic root of 638865422 is about 861.2643301648.

The spelling of 638865422 in words is "six hundred thirty-eight million, eight hundred sixty-five thousand, four hundred twenty-two".