642423656550 has 48 divisors (see below), whose sum is σ = 1715765340240. Its totient is φ = 158135053440.

The previous prime is 642423656527. The next prime is 642423656597. The reversal of 642423656550 is 55656324246.

It is a self number, because there is not a number n which added to its sum of digits gives 642423656550.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164722065 + ... + 164725964.

It is an arithmetic number, because the mean of its divisors is an integer number (35745111255).

Almost surely, 2^642423656550 is an apocalyptic number.

642423656550 is an abundant number, since it is smaller than the sum of its proper divisors (1073341683690).

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

642423656550 is a wasteful number, since it uses less digits than its factorization.

642423656550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329448057 (or 329448052 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 48.

The spelling of 642423656550 in words is "six hundred forty-two billion, four hundred twenty-three million, six hundred fifty-six thousand, five hundred fifty".