66868866 has 48 divisors (see below), whose sum is σ = 159157440. Its totient is φ = 20196000.

The previous prime is 66868861. The next prime is 66868873. The reversal of 66868866 is 66886866.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66868861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3616 + ... + 12116.

It is an arithmetic number, because the mean of its divisors is an integer number (3315780).

Almost surely, 2^66868866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66868866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79578720).

66868866 is an abundant number, since it is smaller than the sum of its proper divisors (92288574).

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

66868866 is a wasteful number, since it uses less digits than its factorization.

66868866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8551 (or 8548 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 54.

The square root of 66868866 is about 8177.3385645942. The cubic root of 66868866 is about 405.8896583510.

The spelling of 66868866 in words is "sixty-six million, eight hundred sixty-eight thousand, eight hundred sixty-six".