166870809 has 24 divisors (see below), whose sum is σ = 275912000. Its totient is φ = 95201568.

The previous prime is 166870801. The next prime is 166870811. The reversal of 166870809 is 908078661.

It is a happy number.

It is not a de Polignac number, because 166870809 - 2³ = 166870801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166870801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45942 + ... + 49440.

Almost surely, 2^166870809 is an apocalyptic number.

It is an amenable number.

166870809 is a deficient number, since it is larger than the sum of its proper divisors (109041191).

166870809 is a wasteful number, since it uses less digits than its factorization.

166870809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4269 (or 4266 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 166870809 is about 12917.8484663662. The cubic root of 166870809 is about 550.5458041860.

The spelling of 166870809 in words is "one hundred sixty-six million, eight hundred seventy thousand, eight hundred nine".