642508840 has 32 divisors (see below), whose sum is σ = 1448657280. Its totient is φ = 256468032.

The previous prime is 642508837. The next prime is 642508861. The reversal of 642508840 is 48805246.

It is a self number, because there is not a number n which added to its sum of digits gives 642508840.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2989 + ... + 35971.

It is an arithmetic number, because the mean of its divisors is an integer number (45270540).

Almost surely, 2^642508840 is an apocalyptic number.

It is an amenable number.

642508840 is an abundant number, since it is smaller than the sum of its proper divisors (806148440).

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

642508840 is a wasteful number, since it uses less digits than its factorization.

642508840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33481 (or 33477 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 37.

The square root of 642508840 is about 25347.7580862687. The cubic root of 642508840 is about 862.8984769400.

The spelling of 642508840 in words is "six hundred forty-two million, five hundred eight thousand, eight hundred forty".