166609 has 2 divisors, whose sum is σ = 166610. Its totient is φ = 166608.

The previous prime is 166603. The next prime is 166613. The reversal of 166609 is 906661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88209 + 78400 = 297^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 166609 - 2³ = 166601 is a prime.

It is not a weakly prime, because it can be changed into another prime (166601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83304 + 83305.

It is an arithmetic number, because the mean of its divisors is an integer number (83305).

2¹⁶⁶⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

166609 is a deficient number, since it is larger than the sum of its proper divisors (1).

166609 is an equidigital number, since it uses as much as digits as its factorization.

166609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 166609 is about 408.1776573993. The cubic root of 166609 is about 55.0257730448.

The spelling of 166609 in words is "one hundred sixty-six thousand, six hundred nine".