165216985 has 16 divisors (see below), whose sum is σ = 203357952. Its totient is φ = 128800000.

The previous prime is 165216977. The next prime is 165217001. The reversal of 165216985 is 589612561.

It is not a de Polignac number, because 165216985 - 2³ = 165216977 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57585 + ... + 60385.

It is an arithmetic number, because the mean of its divisors is an integer number (12709872).

Almost surely, 2^165216985 is an apocalyptic number.

It is an amenable number.

165216985 is a deficient number, since it is larger than the sum of its proper divisors (38140967).

165216985 is a wasteful number, since it uses less digits than its factorization.

165216985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3104.

The product of its digits is 129600, while the sum is 43.

The square root of 165216985 is about 12853.6759333663. The cubic root of 165216985 is about 548.7209783618.

The spelling of 165216985 in words is "one hundred sixty-five million, two hundred sixteen thousand, nine hundred eighty-five".