666849229691 has 2 divisors, whose sum is σ = 666849229692. Its totient is φ = 666849229690.

The previous prime is 666849229639. The next prime is 666849229693. The reversal of 666849229691 is 196922948666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666849229691 is a prime.

Together with 666849229693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666849229693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333424614845 + 333424614846.

It is an arithmetic number, because the mean of its divisors is an integer number (333424614846).

Almost surely, 2^666849229691 is an apocalyptic number.

666849229691 is a deficient number, since it is larger than the sum of its proper divisors (1).

666849229691 is an equidigital number, since it uses as much as digits as its factorization.

666849229691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120932352, while the sum is 68.

The spelling of 666849229691 in words is "six hundred sixty-six billion, eight hundred forty-nine million, two hundred twenty-nine thousand, six hundred ninety-one".