638338636 has 12 divisors (see below), whose sum is σ = 1203022912. Its totient is φ = 294617808.

The previous prime is 638338583. The next prime is 638338643. The reversal of 638338636 is 636833836.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6137820 + ... + 6137923.

Almost surely, 2^638338636 is an apocalyptic number.

It is an amenable number.

638338636 is a deficient number, since it is larger than the sum of its proper divisors (564684276).

638338636 is a wasteful number, since it uses less digits than its factorization.

638338636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12275760 (or 12275758 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 46.

The square root of 638338636 is about 25265.3643551800. The cubic root of 638338636 is about 861.0275422930.

The spelling of 638338636 in words is "six hundred thirty-eight million, three hundred thirty-eight thousand, six hundred thirty-six".