165211985 has 8 divisors (see below), whose sum is σ = 205090920. Its totient is φ = 127611904.

The previous prime is 165211961. The next prime is 165211997. The reversal of 165211985 is 589112561.

It can be written as a sum of positive squares in 4 ways, for example, as 13454224 + 151757761 = 3668^2 + 12319^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165211985 - 2²⁰ = 164163409 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 569552 + ... + 569841.

It is an arithmetic number, because the mean of its divisors is an integer number (25636365).

Almost surely, 2^165211985 is an apocalyptic number.

It is an amenable number.

165211985 is a deficient number, since it is larger than the sum of its proper divisors (39878935).

165211985 is a wasteful number, since it uses less digits than its factorization.

165211985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1139427.

The product of its digits is 21600, while the sum is 38.

The square root of 165211985 is about 12853.4814350043. The cubic root of 165211985 is about 548.7154429492.

The spelling of 165211985 in words is "one hundred sixty-five million, two hundred eleven thousand, nine hundred eighty-five".