646989616 has 80 divisors (see below), whose sum is σ = 1547900928. Its totient is φ = 255110400.

The previous prime is 646989613. The next prime is 646989641. The reversal of 646989616 is 616989646.

It is not an unprimeable number, because it can be changed into a prime (646989613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 627021 + ... + 628051.

Almost surely, 2^646989616 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 646989616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (773950464).

646989616 is an abundant number, since it is smaller than the sum of its proper divisors (900911312).

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

646989616 is a wasteful number, since it uses less digits than its factorization.

646989616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1490 (or 1484 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 55.

The square root of 646989616 is about 25435.9905645524. The cubic root of 646989616 is about 864.8997471436.

The spelling of 646989616 in words is "six hundred forty-six million, nine hundred eighty-nine thousand, six hundred sixteen".