66685668 has 144 divisors (see below), whose sum is σ = 196116480. Its totient is φ = 17527104.

The previous prime is 66685637. The next prime is 66685693. The reversal of 66685668 is 86658666.

It is a self number, because there is not a number n which added to its sum of digits gives 66685668.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 525021 + ... + 525147.

It is an arithmetic number, because the mean of its divisors is an integer number (1361920).

Almost surely, 2^66685668 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 66685668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98058240).

66685668 is an abundant number, since it is smaller than the sum of its proper divisors (129430812).

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

66685668 is a wasteful number, since it uses less digits than its factorization.

66685668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214 (or 205 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 51.

The square root of 66685668 is about 8166.1293156550. The cubic root of 66685668 is about 405.5186526947.

The spelling of 66685668 in words is "sixty-six million, six hundred eighty-five thousand, six hundred sixty-eight".