638340775 has 12 divisors (see below), whose sum is σ = 791870200. Its totient is φ = 510461280.

The previous prime is 638340757. The next prime is 638340811. The reversal of 638340775 is 577043836.

It is not a de Polignac number, because 638340775 - 2¹⁵ = 638308007 is a prime.

It is a congruent number.

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, 90061 + ... + 96889.

Almost surely, 2^638340775 is an apocalyptic number.

638340775 is a deficient number, since it is larger than the sum of its proper divisors (153529425).

638340775 is a wasteful number, since it uses less digits than its factorization.

638340775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10578 (or 10573 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 43.

The square root of 638340775 is about 25265.4066858224. The cubic root of 638340775 is about 861.0285040270.

The spelling of 638340775 in words is "six hundred thirty-eight million, three hundred forty thousand, seven hundred seventy-five".