638889760 has 48 divisors (see below), whose sum is σ = 1534982400. Its totient is φ = 251220736.

The previous prime is 638889679. The next prime is 638889787. The reversal of 638889760 is 67988836.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24400 + ... + 43279.

It is an arithmetic number, because the mean of its divisors is an integer number (31978800).

Almost surely, 2^638889760 is an apocalyptic number.

It is an amenable number.

638889760 is an abundant number, since it is smaller than the sum of its proper divisors (896092640).

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

638889760 is a wasteful number, since it uses less digits than its factorization.

638889760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67753 (or 67745 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 55.

The square root of 638889760 is about 25276.2687119757. The cubic root of 638889760 is about 861.2752668369.

The spelling of 638889760 in words is "six hundred thirty-eight million, eight hundred eighty-nine thousand, seven hundred sixty".