166719689 has 2 divisors, whose sum is σ = 166719690. Its totient is φ = 166719688.

The previous prime is 166719677. The next prime is 166719691. The reversal of 166719689 is 986917661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164737225 + 1982464 = 12835^2 + 1408^2 .

It is a cyclic number.

It is not a de Polignac number, because 166719689 - 2⁴ = 166719673 is a prime.

Together with 166719691, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166719689.

It is not a weakly prime, because it can be changed into another prime (166719089) 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, 83359844 + 83359845.

It is an arithmetic number, because the mean of its divisors is an integer number (83359845).

Almost surely, 2^166719689 is an apocalyptic number.

It is an amenable number.

166719689 is a deficient number, since it is larger than the sum of its proper divisors (1).

166719689 is an equidigital number, since it uses as much as digits as its factorization.

166719689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 979776, while the sum is 53.

The square root of 166719689 is about 12911.9978701981. The cubic root of 166719689 is about 550.3795605907.

The spelling of 166719689 in words is "one hundred sixty-six million, seven hundred nineteen thousand, six hundred eighty-nine".