165218 has 4 divisors (see below), whose sum is σ = 247830. Its totient is φ = 82608.

The previous prime is 165211. The next prime is 165229. The reversal of 165218 is 812561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 812561 = 211 ⋅3851.

It can be written as a sum of positive squares in only one way, i.e., 162409 + 2809 = 403^2 + 53^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 165193 and 165202.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 165218.

It is not an unprimeable number, because it can be changed into a prime (165211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41303 + ... + 41306.

2¹⁶⁵²¹⁸ is an apocalyptic number.

165218 is a deficient number, since it is larger than the sum of its proper divisors (82612).

165218 is an equidigital number, since it uses as much as digits as its factorization.

165218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82611.

The product of its digits is 480, while the sum is 23.

The square root of 165218 is about 406.4701711073. The cubic root of 165218 is about 54.8722102037.

Adding to 165218 its reverse (812561), we get a palindrome (977779).

It can be divided in two parts, 165 and 218, that added together give a palindrome (383).

The spelling of 165218 in words is "one hundred sixty-five thousand, two hundred eighteen".