638224168 has 16 divisors (see below), whose sum is σ = 1197626580. Its totient is φ = 318857088.

The previous prime is 638224159. The next prime is 638224177. The reversal of 638224168 is 861422836.

It is an interprime number because it is at equal distance from previous prime (638224159) and next prime (638224177).

It can be written as a sum of positive squares in 2 ways, for example, as 632924964 + 5299204 = 25158^2 + 2302^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 638224168.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21021 + ... + 41452.

Almost surely, 2^638224168 is an apocalyptic number.

It is an amenable number.

638224168 is a deficient number, since it is larger than the sum of its proper divisors (559402412).

638224168 is a wasteful number, since it uses less digits than its factorization.

638224168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63756 (or 63752 counting only the distinct ones).

The product of its digits is 110592, while the sum is 40.

The square root of 638224168 is about 25263.0989389663. The cubic root of 638224168 is about 860.9760722283.

The spelling of 638224168 in words is "six hundred thirty-eight million, two hundred twenty-four thousand, one hundred sixty-eight".