638771068 has 12 divisors (see below), whose sum is σ = 1203837880. Its totient is φ = 294817392.

The previous prime is 638771009. The next prime is 638771069. The reversal of 638771068 is 860177836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638771069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6141978 + ... + 6142081.

Almost surely, 2^638771068 is an apocalyptic number.

It is an amenable number.

638771068 is a deficient number, since it is larger than the sum of its proper divisors (565066812).

638771068 is a wasteful number, since it uses less digits than its factorization.

638771068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12284076 (or 12284074 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 46.

The square root of 638771068 is about 25273.9207089047. The cubic root of 638771068 is about 861.2219280496.

The spelling of 638771068 in words is "six hundred thirty-eight million, seven hundred seventy-one thousand, sixty-eight".