642906880 has 216 divisors, whose sum is σ = 1937761056. Its totient is φ = 200048640.

The previous prime is 642906871. The next prime is 642906883. The reversal of 642906880 is 88609246.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (642906883) 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 23 ways as a sum of consecutive naturals, for example, 1083864 + ... + 1084456.

It is an arithmetic number, because the mean of its divisors is an integer number (8971116).

Almost surely, 2^642906880 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 642906880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (968880528).

642906880 is an abundant number, since it is smaller than the sum of its proper divisors (1294854176).

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

642906880 is a wasteful number, since it uses less digits than its factorization.

642906880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 618 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 43.

The square root of 642906880 is about 25355.6084525692. The cubic root of 642906880 is about 863.0766312758.

The spelling of 642906880 in words is "six hundred forty-two million, nine hundred six thousand, eight hundred eighty".