638611728366 has 8 divisors (see below), whose sum is σ = 1277223456744. Its totient is φ = 212870576120.

The previous prime is 638611728353. The next prime is 638611728371. The reversal of 638611728366 is 663827116836.

It is a sphenic number, since it is the product of 3 distinct primes.

638611728366 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53217644025 + ... + 53217644036.

It is an arithmetic number, because the mean of its divisors is an integer number (159652932093).

Almost surely, 2^638611728366 is an apocalyptic number.

638611728366 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638611728366 is a wasteful number, since it uses less digits than its factorization.

638611728366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106435288066.

The product of its digits is 10450944, while the sum is 57.

The spelling of 638611728366 in words is "six hundred thirty-eight billion, six hundred eleven million, seven hundred twenty-eight thousand, three hundred sixty-six".