638586428 has 12 divisors (see below), whose sum is σ = 1176343560. Its totient is φ = 302488272.

The previous prime is 638586401. The next prime is 638586437. The reversal of 638586428 is 824685836.

It is a congruent number.

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, 4201151 + ... + 4201302.

It is an arithmetic number, because the mean of its divisors is an integer number (98028630).

Almost surely, 2^638586428 is an apocalyptic number.

It is an amenable number.

638586428 is a deficient number, since it is larger than the sum of its proper divisors (537757132).

638586428 is a wasteful number, since it uses less digits than its factorization.

638586428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8402476 (or 8402474 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 50.

The square root of 638586428 is about 25270.2676677553. The cubic root of 638586428 is about 861.1389398719.

The spelling of 638586428 in words is "six hundred thirty-eight million, five hundred eighty-six thousand, four hundred twenty-eight".