66068781 has 16 divisors (see below), whose sum is σ = 91353600. Its totient is φ = 42428160.

The previous prime is 66068777. The next prime is 66068809. The reversal of 66068781 is 18786066.

It is not a de Polignac number, because 66068781 - 2² = 66068777 is a prime.

It is a super-2 number, since 2×66068781² = 8730167645651922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66068741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20145 + ... + 23193.

It is an arithmetic number, because the mean of its divisors is an integer number (5709600).

Almost surely, 2^66068781 is an apocalyptic number.

It is an amenable number.

66068781 is a deficient number, since it is larger than the sum of its proper divisors (25284819).

66068781 is a wasteful number, since it uses less digits than its factorization.

66068781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3316.

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 66068781 is about 8128.2704802436. The cubic root of 66068781 is about 404.2643374300.

The spelling of 66068781 in words is "sixty-six million, sixty-eight thousand, seven hundred eighty-one".