638633890390 has 16 divisors (see below), whose sum is σ = 1149749314560. Its totient is φ = 255407264640.

The previous prime is 638633890369. The next prime is 638633890421. The reversal of 638633890390 is 93098336836.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5728470 + ... + 5838889.

It is an arithmetic number, because the mean of its divisors is an integer number (71859332160).

Almost surely, 2^638633890390 is an apocalyptic number.

638633890390 is a deficient number, since it is larger than the sum of its proper divisors (511115424170).

638633890390 is a wasteful number, since it uses less digits than its factorization.

638633890390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11572887.

The product of its (nonzero) digits is 15116544, while the sum is 58.

The spelling of 638633890390 in words is "six hundred thirty-eight billion, six hundred thirty-three million, eight hundred ninety thousand, three hundred ninety".