638320760 has 256 divisors, whose sum is σ = 1933424640. Its totient is φ = 183582720.

The previous prime is 638320757. The next prime is 638320807. The reversal of 638320760 is 67023836.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 638320760.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3822197 + ... + 3822363.

It is an arithmetic number, because the mean of its divisors is an integer number (7552440).

Almost surely, 2^638320760 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638320760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (966712320).

638320760 is an abundant number, since it is smaller than the sum of its proper divisors (1295103880).

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

638320760 is a wasteful number, since it uses less digits than its factorization.

638320760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 35.

The square root of 638320760 is about 25265.0105877674. The cubic root of 638320760 is about 861.0195048287.

The spelling of 638320760 in words is "six hundred thirty-eight million, three hundred twenty thousand, seven hundred sixty".