642021260168 has 12 divisors (see below), whose sum is σ = 1203794112165. Its totient is φ = 321009496928.

The previous prime is 642021260129. The next prime is 642021260197. The reversal of 642021260168 is 861062120246.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 555445259524 + 86576000644 = 745282^2 + 294238^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=566578.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2124668 + ... + 2407956.

Almost surely, 2^642021260168 is an apocalyptic number.

It is an amenable number.

642021260168 is a deficient number, since it is larger than the sum of its proper divisors (561772851997).

642021260168 is an frugal number, since it uses more digits than its factorization.

642021260168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566584 (or 283291 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The spelling of 642021260168 in words is "six hundred forty-two billion, twenty-one million, two hundred sixty thousand, one hundred sixty-eight".