166665089 has 2 divisors, whose sum is σ = 166665090. Its totient is φ = 166665088.

The previous prime is 166665043. The next prime is 166665091. The reversal of 166665089 is 980566661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 106090000 + 60575089 = 10300^2 + 7783^2 .

It is an emirp because it is prime and its reverse (980566661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166665089 - 2²⁰ = 165616513 is a prime.

Together with 166665091, 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 (166665689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83332544 + 83332545.

It is an arithmetic number, because the mean of its divisors is an integer number (83332545).

Almost surely, 2^166665089 is an apocalyptic number.

It is an amenable number.

166665089 is a deficient number, since it is larger than the sum of its proper divisors (1).

166665089 is an equidigital number, since it uses as much as digits as its factorization.

166665089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 466560, while the sum is 47.

The square root of 166665089 is about 12909.8833844462. The cubic root of 166665089 is about 550.3194716968.

The spelling of 166665089 in words is "one hundred sixty-six million, six hundred sixty-five thousand, eighty-nine".