638630426 has 24 divisors (see below), whose sum is σ = 1129622580. Its totient is φ = 269946432.

The previous prime is 638630417. The next prime is 638630437. The reversal of 638630426 is 624036836.

It can be written as a sum of positive squares in 2 ways, for example, as 636805225 + 1825201 = 25235^2 + 1351^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 638630426.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37481 + ... + 51788.

Almost surely, 2^638630426 is an apocalyptic number.

638630426 is a deficient number, since it is larger than the sum of its proper divisors (490992154).

638630426 is a wasteful number, since it uses less digits than its factorization.

638630426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89358 (or 89351 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 38.

The square root of 638630426 is about 25271.1382015136. The cubic root of 638630426 is about 861.1587166368.

The spelling of 638630426 in words is "six hundred thirty-eight million, six hundred thirty thousand, four hundred twenty-six".