638285408 has 12 divisors (see below), whose sum is σ = 1256624460. Its totient is φ = 319142688.

The previous prime is 638285407. The next prime is 638285419. The reversal of 638285408 is 804582836.

It is a super-4 number, since 4×638285408⁴ (a number of 36 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638285407) by changing a digit.

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 as a sum of consecutive naturals, namely, 9973178 + ... + 9973241.

It is an arithmetic number, because the mean of its divisors is an integer number (104718705).

Almost surely, 2^638285408 is an apocalyptic number.

It is an amenable number.

638285408 is a deficient number, since it is larger than the sum of its proper divisors (618339052).

638285408 is a wasteful number, since it uses less digits than its factorization.

638285408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19946429 (or 19946421 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 44.

The square root of 638285408 is about 25264.3109543878. The cubic root of 638285408 is about 861.0036093075.

The spelling of 638285408 in words is "six hundred thirty-eight million, two hundred eighty-five thousand, four hundred eight".