166850009 has 4 divisors (see below), whose sum is σ = 168470016. Its totient is φ = 165230004.

The previous prime is 166849999. The next prime is 166850063. The reversal of 166850009 is 900058661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 900058661 = 2161 ⋅416501.

It is a cyclic number.

It is not a de Polignac number, because 166850009 - 2⁴ = 166849993 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166850069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 809849 + ... + 810054.

It is an arithmetic number, because the mean of its divisors is an integer number (42117504).

Almost surely, 2^166850009 is an apocalyptic number.

It is an amenable number.

166850009 is a deficient number, since it is larger than the sum of its proper divisors (1620007).

166850009 is a wasteful number, since it uses less digits than its factorization.

166850009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620006.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 166850009 is about 12917.0433536471. The cubic root of 166850009 is about 550.5229285482.

The spelling of 166850009 in words is "one hundred sixty-six million, eight hundred fifty thousand, nine".