166959809 has 2 divisors, whose sum is σ = 166959810. Its totient is φ = 166959808.

The previous prime is 166959797. The next prime is 166959847. The reversal of 166959809 is 908959661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99062209 + 67897600 = 9953^2 + 8240^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166959809 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166959509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83479904 + 83479905.

It is an arithmetic number, because the mean of its divisors is an integer number (83479905).

Almost surely, 2^166959809 is an apocalyptic number.

It is an amenable number.

166959809 is a deficient number, since it is larger than the sum of its proper divisors (1).

166959809 is an equidigital number, since it uses as much as digits as its factorization.

166959809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1049760, while the sum is 53.

The square root of 166959809 is about 12921.2928532713. The cubic root of 166959809 is about 550.6436640581.

The spelling of 166959809 in words is "one hundred sixty-six million, nine hundred fifty-nine thousand, eight hundred nine".