638608929 has 16 divisors (see below), whose sum is σ = 973501440. Its totient is φ = 364775760.

The previous prime is 638608877. The next prime is 638608967. The reversal of 638608929 is 929806836.

It is not a de Polignac number, because 638608929 - 2¹² = 638604833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638600929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72684 + ... + 80994.

It is an arithmetic number, because the mean of its divisors is an integer number (60843840).

Almost surely, 2^638608929 is an apocalyptic number.

It is an amenable number.

638608929 is a deficient number, since it is larger than the sum of its proper divisors (334892511).

638608929 is a wasteful number, since it uses less digits than its factorization.

638608929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11980.

The product of its (nonzero) digits is 1119744, while the sum is 51.

The square root of 638608929 is about 25270.7128708313. The cubic root of 638608929 is about 861.1490540130.

The spelling of 638608929 in words is "six hundred thirty-eight million, six hundred eight thousand, nine hundred twenty-nine".