66565666 has 8 divisors (see below), whose sum is σ = 100837404. Its totient is φ = 32953200.

The previous prime is 66565661. The next prime is 66565669. The reversal of 66565666 is 66656566.

It can be written as a sum of positive squares in 2 ways, for example, as 52345225 + 14220441 = 7235^2 + 3771^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66565661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164565 + ... + 164968.

Almost surely, 2^66565666 is an apocalyptic number.

66565666 is a deficient number, since it is larger than the sum of its proper divisors (34271738).

66565666 is a wasteful number, since it uses less digits than its factorization.

66565666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329636.

The product of its digits is 1166400, while the sum is 46.

The square root of 66565666 is about 8158.7784624906. The cubic root of 66565666 is about 405.2752607234.

The spelling of 66565666 in words is "sixty-six million, five hundred sixty-five thousand, six hundred sixty-six".