6666766157 has 2 divisors, whose sum is σ = 6666766158. Its totient is φ = 6666766156.

The previous prime is 6666766147. The next prime is 6666766159. The reversal of 6666766157 is 7516676666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3712952356 + 2953813801 = 60934^2 + 54349^2 .

It is a cyclic number.

It is not a de Polignac number, because 6666766157 - 2¹² = 6666762061 is a prime.

Together with 6666766159, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6666766159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333383078 + 3333383079.

It is an arithmetic number, because the mean of its divisors is an integer number (3333383079).

Almost surely, 2^6666766157 is an apocalyptic number.

It is an amenable number.

6666766157 is a deficient number, since it is larger than the sum of its proper divisors (1).

6666766157 is an equidigital number, since it uses as much as digits as its factorization.

6666766157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11430720, while the sum is 56.

The square root of 6666766157 is about 81650.2673418771. The cubic root of 6666766157 is about 1882.0814201143.

The spelling of 6666766157 in words is "six billion, six hundred sixty-six million, seven hundred sixty-six thousand, one hundred fifty-seven".