6766642661 has 2 divisors, whose sum is σ = 6766642662. Its totient is φ = 6766642660.

The previous prime is 6766642643. The next prime is 6766642697. The reversal of 6766642661 is 1662466676.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6663620161 + 103022500 = 81631^2 + 10150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6766642661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6766642261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3383321330 + 3383321331.

It is an arithmetic number, because the mean of its divisors is an integer number (3383321331).

Almost surely, 2^6766642661 is an apocalyptic number.

It is an amenable number.

6766642661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6766642661 is an equidigital number, since it uses as much as digits as its factorization.

6766642661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2612736, while the sum is 50.

The square root of 6766642661 is about 82259.6052810856. The cubic root of 6766642661 is about 1891.4335177586.

The spelling of 6766642661 in words is "six billion, seven hundred sixty-six million, six hundred forty-two thousand, six hundred sixty-one".