166913844791 has 2 divisors, whose sum is σ = 166913844792. Its totient is φ = 166913844790.

The previous prime is 166913844737. The next prime is 166913844821. The reversal of 166913844791 is 197448319661.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (197448319661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166913844791 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166913844791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166913844731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83456922395 + 83456922396.

It is an arithmetic number, because the mean of its divisors is an integer number (83456922396).

Almost surely, 2^166913844791 is an apocalyptic number.

166913844791 is a deficient number, since it is larger than the sum of its proper divisors (1).

166913844791 is an equidigital number, since it uses as much as digits as its factorization.

166913844791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7838208, while the sum is 59.

The spelling of 166913844791 in words is "one hundred sixty-six billion, nine hundred thirteen million, eight hundred forty-four thousand, seven hundred ninety-one".