638927099940 has 24 divisors (see below), whose sum is σ = 1788995880000. Its totient is φ = 170380559968.

The previous prime is 638927099939. The next prime is 638927099947. The reversal of 638927099940 is 49990729836.

It is not an unprimeable number, because it can be changed into a prime (638927099947) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5324392440 + ... + 5324392559.

It is an arithmetic number, because the mean of its divisors is an integer number (74541495000).

Almost surely, 2^638927099940 is an apocalyptic number.

638927099940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638927099940 is an abundant number, since it is smaller than the sum of its proper divisors (1150068780060).

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

638927099940 is a wasteful number, since it uses less digits than its factorization.

638927099940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10648785011 (or 10648785009 counting only the distinct ones).

The product of its (nonzero) digits is 52907904, while the sum is 66.

The spelling of 638927099940 in words is "six hundred thirty-eight billion, nine hundred twenty-seven million, ninety-nine thousand, nine hundred forty".