6666788666 has 8 divisors (see below), whose sum is σ = 10526508480. Its totient is φ = 3157952508.

The previous prime is 6666788621. The next prime is 6666788677. The reversal of 6666788666 is 6668876666.

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

It is a super-2 number, since 2×6666788666² = 88892142234212119112, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87720866 + ... + 87720941.

It is an arithmetic number, because the mean of its divisors is an integer number (1315813560).

Almost surely, 2^6666788666 is an apocalyptic number.

6666788666 is a deficient number, since it is larger than the sum of its proper divisors (3859719814).

6666788666 is a wasteful number, since it uses less digits than its factorization.

6666788666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175441828.

The product of its digits is 125411328, while the sum is 65.

The square root of 6666788666 is about 81650.4051796438. The cubic root of 6666788666 is about 1882.0835382688.

The spelling of 6666788666 in words is "six billion, six hundred sixty-six million, seven hundred eighty-eight thousand, six hundred sixty-six".