642028450856 has 128 divisors (see below), whose sum is σ = 1360164234240. Its totient is φ = 281892864000.

The previous prime is 642028450829. The next prime is 642028450867. The reversal of 642028450856 is 658054820246.

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 31 ways as a sum of consecutive naturals, for example, 413410976 + ... + 413412528.

It is an arithmetic number, because the mean of its divisors is an integer number (10626283080).

Almost surely, 2^642028450856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642028450856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (680082117120).

642028450856 is an abundant number, since it is smaller than the sum of its proper divisors (718135783384).

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

642028450856 is a wasteful number, since it uses less digits than its factorization.

642028450856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2427 (or 2423 counting only the distinct ones).

The product of its (nonzero) digits is 3686400, while the sum is 50.

The spelling of 642028450856 in words is "six hundred forty-two billion, twenty-eight million, four hundred fifty thousand, eight hundred fifty-six".