166044209 has 4 divisors (see below), whose sum is σ = 166207860. Its totient is φ = 165880560.

The previous prime is 166044191. The next prime is 166044217. The reversal of 166044209 is 902440661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 902440661 = 313 ⋅2883197.

It can be written as a sum of positive squares in 2 ways, for example, as 126000625 + 40043584 = 11225^2 + 6328^2 .

It is a cyclic number.

It is not a de Polignac number, because 166044209 - 2⁸ = 166043953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166044289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80294 + ... + 82335.

It is an arithmetic number, because the mean of its divisors is an integer number (41551965).

Almost surely, 2^166044209 is an apocalyptic number.

It is an amenable number.

166044209 is a deficient number, since it is larger than the sum of its proper divisors (163651).

166044209 is a wasteful number, since it uses less digits than its factorization.

166044209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163650.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 166044209 is about 12885.8142544428. The cubic root of 166044209 is about 549.6352501691.

The spelling of 166044209 in words is "one hundred sixty-six million, forty-four thousand, two hundred nine".