165666087 has 8 divisors (see below), whose sum is σ = 245431280. Its totient is φ = 110444040.

The previous prime is 165666047. The next prime is 165666089. The reversal of 165666087 is 780666561.

It is not a de Polignac number, because 165666087 - 2¹⁰ = 165665063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165666089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3067864 + ... + 3067917.

It is an arithmetic number, because the mean of its divisors is an integer number (30678910).

Almost surely, 2^165666087 is an apocalyptic number.

165666087 is a deficient number, since it is larger than the sum of its proper divisors (79765193).

165666087 is an equidigital number, since it uses as much as digits as its factorization.

165666087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6135790 (or 6135784 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 165666087 is about 12871.1338661363. The cubic root of 165666087 is about 549.2177165096.

The spelling of 165666087 in words is "one hundred sixty-five million, six hundred sixty-six thousand, eighty-seven".