642805828 has 12 divisors (see below), whose sum is σ = 1285611712. Its totient is φ = 275488200.

The previous prime is 642805741. The next prime is 642805829. The reversal of 642805828 is 828508246.

642805828 is an admirable number.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (642805829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11478648 + ... + 11478703.

Almost surely, 2^642805828 is an apocalyptic number.

It is an amenable number.

642805828 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

642805828 is a wasteful number, since it uses less digits than its factorization.

642805828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22957362 (or 22957360 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 43.

The square root of 642805828 is about 25353.6156790309. The cubic root of 642805828 is about 863.0314094911.

The spelling of 642805828 in words is "six hundred forty-two million, eight hundred five thousand, eight hundred twenty-eight".