6667447691 has 2 divisors, whose sum is σ = 6667447692. Its totient is φ = 6667447690.

The previous prime is 6667447649. The next prime is 6667447711. The reversal of 6667447691 is 1967447666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6667447691 is a prime.

It is not a weakly prime, because it can be changed into another prime (6667447601) 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, 3333723845 + 3333723846.

It is an arithmetic number, because the mean of its divisors is an integer number (3333723846).

Almost surely, 2^6667447691 is an apocalyptic number.

6667447691 is a deficient number, since it is larger than the sum of its proper divisors (1).

6667447691 is an equidigital number, since it uses as much as digits as its factorization.

6667447691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9144576, while the sum is 56.

The square root of 6667447691 is about 81654.4407304343. The cubic root of 6667447691 is about 1882.1455520958.

The spelling of 6667447691 in words is "six billion, six hundred sixty-seven million, four hundred forty-seven thousand, six hundred ninety-one".