638630399 has 16 divisors (see below), whose sum is σ = 710311680. Its totient is φ = 569300160.

The previous prime is 638630393. The next prime is 638630417. The reversal of 638630399 is 993036836.

It is a de Polignac number, because none of the positive numbers 2^k-638630399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638630393) 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 15 ways as a sum of consecutive naturals, for example, 169862 + ... + 173580.

It is an arithmetic number, because the mean of its divisors is an integer number (44394480).

Almost surely, 2^638630399 is an apocalyptic number.

638630399 is a deficient number, since it is larger than the sum of its proper divisors (71681281).

638630399 is a wasteful number, since it uses less digits than its factorization.

638630399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4030.

The product of its (nonzero) digits is 629856, while the sum is 47.

The square root of 638630399 is about 25271.1376673073. The cubic root of 638630399 is about 861.1587045008.

The spelling of 638630399 in words is "six hundred thirty-eight million, six hundred thirty thousand, three hundred ninety-nine".