165636665 has 4 divisors (see below), whose sum is σ = 198764004. Its totient is φ = 132509328.

The previous prime is 165636641. The next prime is 165636673. The reversal of 165636665 is 566636561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37063744 + 128572921 = 6088^2 + 11339^2 .

It is a cyclic number.

It is not a de Polignac number, because 165636665 - 2²² = 161442361 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16563662 + ... + 16563671.

It is an arithmetic number, because the mean of its divisors is an integer number (49691001).

Almost surely, 2^165636665 is an apocalyptic number.

It is an amenable number.

165636665 is a deficient number, since it is larger than the sum of its proper divisors (33127339).

165636665 is an equidigital number, since it uses as much as digits as its factorization.

165636665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33127338.

The product of its digits is 583200, while the sum is 44.

The square root of 165636665 is about 12869.9908702376. The cubic root of 165636665 is about 549.1852012240.

The spelling of 165636665 in words is "one hundred sixty-five million, six hundred thirty-six thousand, six hundred sixty-five".