166009825 has 6 divisors (see below), whose sum is σ = 205852214. Its totient is φ = 132807840.

The previous prime is 166009819. The next prime is 166009829. The reversal of 166009825 is 528900661.

It can be written as a sum of positive squares in 3 ways, for example, as 13017664 + 152992161 = 3608^2 + 12369^2 .

It is not a de Polignac number, because 166009825 - 2⁵ = 166009793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166009829) 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, 3320172 + ... + 3320221.

Almost surely, 2^166009825 is an apocalyptic number.

It is an amenable number.

166009825 is a deficient number, since it is larger than the sum of its proper divisors (39842389).

166009825 is an equidigital number, since it uses as much as digits as its factorization.

166009825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6640403 (or 6640398 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 166009825 is about 12884.4800050293. The cubic root of 166009825 is about 549.5973085406.

The spelling of 166009825 in words is "one hundred sixty-six million, nine thousand, eight hundred twenty-five".