66966666 has 64 divisors (see below), whose sum is σ = 149361408. Its totient is φ = 19888128.

The previous prime is 66966661. The next prime is 66966673. The reversal of 66966666 is 66666966.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66966661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 400915 + ... + 401081.

It is an arithmetic number, because the mean of its divisors is an integer number (2333772).

Almost surely, 2^66966666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66966666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74680704).

66966666 is an abundant number, since it is smaller than the sum of its proper divisors (82394742).

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

66966666 is a wasteful number, since it uses less digits than its factorization.

66966666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335.

The product of its digits is 2519424, while the sum is 51.

The square root of 66966666 is about 8183.3163204168. The cubic root of 66966666 is about 406.0874418339.

The spelling of 66966666 in words is "sixty-six million, nine hundred sixty-six thousand, six hundred sixty-six".