638533375 has 8 divisors (see below), whose sum is σ = 796889808. Its totient is φ = 510826600.

The previous prime is 638533373. The next prime is 638533403. The reversal of 638533375 is 573335836.

It is not a de Polignac number, because 638533375 - 2¹ = 638533373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638533373) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2554009 + ... + 2554258.

It is an arithmetic number, because the mean of its divisors is an integer number (99611226).

Almost surely, 2^638533375 is an apocalyptic number.

638533375 is a deficient number, since it is larger than the sum of its proper divisors (158356433).

638533375 is an equidigital number, since it uses as much as digits as its factorization.

638533375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5108282 (or 5108272 counting only the distinct ones).

The product of its digits is 680400, while the sum is 43.

The square root of 638533375 is about 25269.2179340794. The cubic root of 638533375 is about 861.1150917456.

The spelling of 638533375 in words is "six hundred thirty-eight million, five hundred thirty-three thousand, three hundred seventy-five".