165866825 has 6 divisors (see below), whose sum is σ = 205674894. Its totient is φ = 132693440.

The previous prime is 165866821. The next prime is 165866837. The reversal of 165866825 is 528668561.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 25775929 + 140090896 = 5077^2 + 11836^2 .

It is not a de Polignac number, because 165866825 - 2² = 165866821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 165866825.

It is not an unprimeable number, because it can be changed into a prime (165866821) 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, 3317312 + ... + 3317361.

It is an arithmetic number, because the mean of its divisors is an integer number (34279149).

Almost surely, 2^165866825 is an apocalyptic number.

It is an amenable number.

165866825 is a deficient number, since it is larger than the sum of its proper divisors (39808069).

165866825 is an equidigital number, since it uses as much as digits as its factorization.

165866825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6634683 (or 6634678 counting only the distinct ones).

The product of its digits is 691200, while the sum is 47.

The square root of 165866825 is about 12878.9294974388. The cubic root of 165866825 is about 549.4394564531.

The spelling of 165866825 in words is "one hundred sixty-five million, eight hundred sixty-six thousand, eight hundred twenty-five".