638655500770 has 128 divisors (see below), whose sum is σ = 1387922688000. Its totient is φ = 211369084416.

The previous prime is 638655500701. The next prime is 638655500773. The reversal of 638655500770 is 77005556836.

It is not an unprimeable number, because it can be changed into a prime (638655500773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11741196 + ... + 11795464.

It is an arithmetic number, because the mean of its divisors is an integer number (10843146000).

Almost surely, 2^638655500770 is an apocalyptic number.

638655500770 is an abundant number, since it is smaller than the sum of its proper divisors (749267187230).

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

638655500770 is a wasteful number, since it uses less digits than its factorization.

638655500770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54417 (or 54403 counting only the distinct ones).

The product of its (nonzero) digits is 5292000, while the sum is 52.

The spelling of 638655500770 in words is "six hundred thirty-eight billion, six hundred fifty-five million, five hundred thousand, seven hundred seventy".