166867009 has 2 divisors, whose sum is σ = 166867010. Its totient is φ = 166867008.

The previous prime is 166866971. The next prime is 166867013. The reversal of 166867009 is 900768661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108680625 + 58186384 = 10425^2 + 7628^2 .

It is a cyclic number.

It is not a de Polignac number, because 166867009 - 2¹⁷ = 166735937 is a prime.

It is not a weakly prime, because it can be changed into another prime (166865009) 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, 83433504 + 83433505.

It is an arithmetic number, because the mean of its divisors is an integer number (83433505).

Almost surely, 2^166867009 is an apocalyptic number.

It is an amenable number.

166867009 is a deficient number, since it is larger than the sum of its proper divisors (1).

166867009 is an equidigital number, since it uses as much as digits as its factorization.

166867009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 166867009 is about 12917.7013822119. The cubic root of 166867009 is about 550.5416251248.

The spelling of 166867009 in words is "one hundred sixty-six million, eight hundred sixty-seven thousand, nine".