212165 has 4 divisors (see below), whose sum is σ = 254604. Its totient is φ = 169728.

The previous prime is 212161. The next prime is 212167. The reversal of 212165 is 561212.

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 98596 + 113569 = 314^2 + 337^2 .

It is a cyclic number.

It is not a de Polignac number, because 212165 - 2² = 212161 is a prime.

It is an Ulam number.

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

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21212 + ... + 21221.

It is an arithmetic number, because the mean of its divisors is an integer number (63651).

2²¹²¹⁶⁵ is an apocalyptic number.

It is an amenable number.

212165 is a deficient number, since it is larger than the sum of its proper divisors (42439).

212165 is an equidigital number, since it uses as much as digits as its factorization.

212165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42438.

The product of its digits is 120, while the sum is 17.

The square root of 212165 is about 460.6137210288. The cubic root of 212165 is about 59.6427849177.

Adding to 212165 its reverse (561212), we get a palindrome (773377).

It can be divided in two parts, 212 and 165, that multiplied together give a triangular number (34980 = T₂₆₄).

The spelling of 212165 in words is "two hundred twelve thousand, one hundred sixty-five".