642798920 has 32 divisors (see below), whose sum is σ = 1496172600. Its totient is φ = 248252928.

The previous prime is 642798913. The next prime is 642798941. The reversal of 642798920 is 29897246.

It can be written as a sum of positive squares in 4 ways, for example, as 540748516 + 102050404 = 23254^2 + 10102^2 .

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275909 + ... + 278228.

Almost surely, 2^642798920 is an apocalyptic number.

It is an amenable number.

642798920 is an abundant number, since it is smaller than the sum of its proper divisors (853373680).

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

642798920 is a wasteful number, since it uses less digits than its factorization.

642798920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554177 (or 554173 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 642798920 is about 25353.4794456303. The cubic root of 642798920 is about 863.0283179186.

The spelling of 642798920 in words is "six hundred forty-two million, seven hundred ninety-eight thousand, nine hundred twenty".