638072636 has 12 divisors (see below), whose sum is σ = 1117509120. Its totient is φ = 318784320.

The previous prime is 638072629. The next prime is 638072653. The reversal of 638072636 is 636270836.

It is a junction number, because it is equal to n+sod(n) for n = 638072593 and 638072602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57245 + ... + 67476.

It is an arithmetic number, because the mean of its divisors is an integer number (93125760).

Almost surely, 2^638072636 is an apocalyptic number.

It is an amenable number.

638072636 is a deficient number, since it is larger than the sum of its proper divisors (479436484).

638072636 is a wasteful number, since it uses less digits than its factorization.

638072636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126004 (or 126002 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 41.

The square root of 638072636 is about 25260.0996830971. The cubic root of 638072636 is about 860.9079270220.

The spelling of 638072636 in words is "six hundred thirty-eight million, seventy-two thousand, six hundred thirty-six".