66783668 has 36 divisors (see below), whose sum is σ = 139642020. Its totient is φ = 27844992.

The previous prime is 66783653. The next prime is 66783671. The reversal of 66783668 is 86638766.

It can be written as a sum of positive squares in 2 ways, for example, as 35736484 + 31047184 = 5978^2 + 5572^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2648 + ... + 11856.

It is an arithmetic number, because the mean of its divisors is an integer number (3878945).

Almost surely, 2^66783668 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 66783668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69821010).

66783668 is an abundant number, since it is smaller than the sum of its proper divisors (72858352).

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

66783668 is a wasteful number, since it uses less digits than its factorization.

66783668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9264 (or 9255 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 50.

The square root of 66783668 is about 8172.1275075711. The cubic root of 66783668 is about 405.7172029858.

The spelling of 66783668 in words is "sixty-six million, seven hundred eighty-three thousand, six hundred sixty-eight".