166532809 has 2 divisors, whose sum is σ = 166532810. Its totient is φ = 166532808.

The previous prime is 166532803. The next prime is 166532831. The reversal of 166532809 is 908235661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142277184 + 24255625 = 11928^2 + 4925^2 .

It is a cyclic number.

It is not a de Polignac number, because 166532809 - 2²⁷ = 32315081 is a prime.

It is not a weakly prime, because it can be changed into another prime (166532803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83266404 + 83266405.

It is an arithmetic number, because the mean of its divisors is an integer number (83266405).

Almost surely, 2^166532809 is an apocalyptic number.

It is an amenable number.

166532809 is a deficient number, since it is larger than the sum of its proper divisors (1).

166532809 is an equidigital number, since it uses as much as digits as its factorization.

166532809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 166532809 is about 12904.7591608677. The cubic root of 166532809 is about 550.1738392635.

The spelling of 166532809 in words is "one hundred sixty-six million, five hundred thirty-two thousand, eight hundred nine".