642021708 has 12 divisors (see below), whose sum is σ = 1498050680. Its totient is φ = 214007232.

The previous prime is 642021707. The next prime is 642021713. The reversal of 642021708 is 807120246.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (642021707) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 26750893 + ... + 26750916.

Almost surely, 2^642021708 is an apocalyptic number.

It is an amenable number.

642021708 is an abundant number, since it is smaller than the sum of its proper divisors (856028972).

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

642021708 is a wasteful number, since it uses less digits than its factorization.

642021708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53501816 (or 53501814 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 642021708 is about 25338.1472882293. The cubic root of 642021708 is about 862.6803467443.

The spelling of 642021708 in words is "six hundred forty-two million, twenty-one thousand, seven hundred eight".