6686561616 has 160 divisors (see below), whose sum is σ = 20490878976. Its totient is φ = 1838592000.

The previous prime is 6686561599. The next prime is 6686561641. The reversal of 6686561616 is 6161656866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1987776 + ... + 1991136.

Almost surely, 2^6686561616 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 6686561616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10245439488).

6686561616 is an abundant number, since it is smaller than the sum of its proper divisors (13804317360).

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

6686561616 is a wasteful number, since it uses less digits than its factorization.

6686561616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3601 (or 3595 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 51.

The square root of 6686561616 is about 81771.3985205096. The cubic root of 6686561616 is about 1883.9423849024.

The spelling of 6686561616 in words is "six billion, six hundred eighty-six million, five hundred sixty-one thousand, six hundred sixteen".