638397790 has 8 divisors (see below), whose sum is σ = 1149116040. Its totient is φ = 255359112.

The previous prime is 638397769. The next prime is 638397791. The reversal of 638397790 is 97793836.

638397790 is digitally balanced in base 2 and base 6, because in such bases it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638397791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31919880 + ... + 31919899.

It is an arithmetic number, because the mean of its divisors is an integer number (143639505).

Almost surely, 2^638397790 is an apocalyptic number.

638397790 is a deficient number, since it is larger than the sum of its proper divisors (510718250).

638397790 is a wasteful number, since it uses less digits than its factorization.

638397790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63839786.

The product of its (nonzero) digits is 1714608, while the sum is 52.

The square root of 638397790 is about 25266.5349820667. The cubic root of 638397790 is about 861.0541382340.

The spelling of 638397790 in words is "six hundred thirty-eight million, three hundred ninety-seven thousand, seven hundred ninety".