638351975 has 12 divisors (see below), whose sum is σ = 804974520. Its totient is φ = 502024800.

The previous prime is 638351963. The next prime is 638351977. The reversal of 638351975 is 579153836.

638351975 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-638351975 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638351977) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 214916 + ... + 217865.

It is an arithmetic number, because the mean of its divisors is an integer number (67081210).

Almost surely, 2^638351975 is an apocalyptic number.

638351975 is a deficient number, since it is larger than the sum of its proper divisors (166622545).

638351975 is a wasteful number, since it uses less digits than its factorization.

638351975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432850 (or 432845 counting only the distinct ones).

The product of its digits is 680400, while the sum is 47.

The square root of 638351975 is about 25265.6283317870. The cubic root of 638351975 is about 861.0335397191.

The spelling of 638351975 in words is "six hundred thirty-eight million, three hundred fifty-one thousand, nine hundred seventy-five".