638408075 has 12 divisors (see below), whose sum is σ = 833291160. Its totient is φ = 483845760.

The previous prime is 638408063. The next prime is 638408129. The reversal of 638408075 is 570804836.

It is a happy number.

It is not a de Polignac number, because 638408075 - 2¹⁶ = 638342539 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 671534 + ... + 672483.

It is an arithmetic number, because the mean of its divisors is an integer number (69440930).

Almost surely, 2^638408075 is an apocalyptic number.

638408075 is a deficient number, since it is larger than the sum of its proper divisors (194883085).

638408075 is a wasteful number, since it uses less digits than its factorization.

638408075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344046 (or 1344041 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 638408075 is about 25266.7385113315. The cubic root of 638408075 is about 861.0587622549.

The spelling of 638408075 in words is "six hundred thirty-eight million, four hundred eight thousand, seventy-five".