646289776 has 80 divisors (see below), whose sum is σ = 1404374400. Its totient is φ = 285638400.

The previous prime is 646289771. The next prime is 646289801. The reversal of 646289776 is 677982646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646289771) 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 15 ways as a sum of consecutive naturals, for example, 1131571 + ... + 1132141.

It is an arithmetic number, because the mean of its divisors is an integer number (17554680).

Almost surely, 2^646289776 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 646289776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (702187200).

646289776 is an abundant number, since it is smaller than the sum of its proper divisors (758084624).

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

646289776 is a wasteful number, since it uses less digits than its factorization.

646289776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758 (or 752 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 55.

The square root of 646289776 is about 25422.2299572638. The cubic root of 646289776 is about 864.5877844781.

The spelling of 646289776 in words is "six hundred forty-six million, two hundred eighty-nine thousand, seven hundred seventy-six".