2166709 has 2 divisors, whose sum is σ = 2166710. Its totient is φ = 2166708.

The previous prime is 2166691. The next prime is 2166721. The reversal of 2166709 is 9076612.

2166709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2093809 + 72900 = 1447^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166709 - 2⁷ = 2166581 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2166509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083354 + 1083355.

It is an arithmetic number, because the mean of its divisors is an integer number (1083355).

2^2166709 is an apocalyptic number.

It is an amenable number.

2166709 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166709 is an equidigital number, since it uses as much as digits as its factorization.

2166709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 2166709 is about 1471.9745242361. The cubic root of 2166709 is about 129.3997773575.

Subtracting 2166709 from its reverse (9076612), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 2166709 in words is "two million, one hundred sixty-six thousand, seven hundred nine".