638458975 has 36 divisors (see below), whose sum is σ = 1004687928. Its totient is φ = 397992000.

The previous prime is 638458963. The next prime is 638458979. The reversal of 638458975 is 579854836.

638458975 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 638458975 - 2¹³ = 638450783 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638458979) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 10216 + ... + 37165.

It is an arithmetic number, because the mean of its divisors is an integer number (27907998).

Almost surely, 2^638458975 is an apocalyptic number.

638458975 is a deficient number, since it is larger than the sum of its proper divisors (366228953).

638458975 is a wasteful number, since it uses less digits than its factorization.

638458975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47416 (or 47404 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 55.

The square root of 638458975 is about 25267.7457443279. The cubic root of 638458975 is about 861.0816455944.

The spelling of 638458975 in words is "six hundred thirty-eight million, four hundred fifty-eight thousand, nine hundred seventy-five".