166600009 has 6 divisors (see below), whose sum is σ = 168984650. Its totient is φ = 164248560.

The previous prime is 166600003. The next prime is 166600013. The reversal of 166600009 is 900006661.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 87834384 + 78765625 = 9372^2 + 8875^2 .

It is not a de Polignac number, because 166600009 - 2³ = 166600001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166600009.

It is not an unprimeable number, because it can be changed into a prime (166600001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11484 + ... + 21565.

Almost surely, 2^166600009 is an apocalyptic number.

It is an amenable number.

166600009 is a deficient number, since it is larger than the sum of its proper divisors (2384641).

166600009 is an frugal number, since it uses more digits than its factorization.

166600009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33191 (or 33120 counting only the distinct ones).

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

The square root of 166600009 is about 12907.3625888483. The cubic root of 166600009 is about 550.2478321108.

The spelling of 166600009 in words is "one hundred sixty-six million, six hundred thousand, nine".