638783880 has 64 divisors (see below), whose sum is σ = 2190119040. Its totient is φ = 146007552.

The previous prime is 638783839. The next prime is 638783881. The reversal of 638783880 is 88387836.

It is not an unprimeable number, because it can be changed into a prime (638783881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 379389 + ... + 381068.

It is an arithmetic number, because the mean of its divisors is an integer number (34220610).

Almost surely, 2^638783880 is an apocalyptic number.

638783880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638783880 is an abundant number, since it is smaller than the sum of its proper divisors (1551335160).

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

638783880 is a wasteful number, since it uses less digits than its factorization.

638783880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760478 (or 760474 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 51.

The square root of 638783880 is about 25274.1741704848. The cubic root of 638783880 is about 861.2276859297.

The spelling of 638783880 in words is "six hundred thirty-eight million, seven hundred eighty-three thousand, eight hundred eighty".