638888424 has 64 divisors (see below), whose sum is σ = 1745763840. Its totient is φ = 193966080.

The previous prime is 638888417. The next prime is 638888429. The reversal of 638888424 is 424888836.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (638888429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12609 + ... + 37904.

It is an arithmetic number, because the mean of its divisors is an integer number (27277560).

Almost surely, 2^638888424 is an apocalyptic number.

It is an amenable number.

638888424 is an abundant number, since it is smaller than the sum of its proper divisors (1106875416).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638888424 is a wasteful number, since it uses less digits than its factorization.

638888424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50570 (or 50566 counting only the distinct ones).

The product of its digits is 2359296, while the sum is 51.

The square root of 638888424 is about 25276.2422840105. The cubic root of 638888424 is about 861.2746664910.

The spelling of 638888424 in words is "six hundred thirty-eight million, eight hundred eighty-eight thousand, four hundred twenty-four".