212540165 has 8 divisors (see below), whose sum is σ = 259229688. Its totient is φ = 167244480.

The previous prime is 212540143. The next prime is 212540177. The reversal of 212540165 is 561045212.

It can be written as a sum of positive squares in 4 ways, for example, as 9278116 + 203262049 = 3046^2 + 14257^2 .

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

It is not a de Polignac number, because 212540165 - 2¹⁸ = 212278021 is a prime.

It is a Duffinian number.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 348122 + ... + 348731.

It is an arithmetic number, because the mean of its divisors is an integer number (32403711).

Almost surely, 2^212540165 is an apocalyptic number.

It is an amenable number.

212540165 is a deficient number, since it is larger than the sum of its proper divisors (46689523).

212540165 is an equidigital number, since it uses as much as digits as its factorization.

212540165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696919.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 212540165 is about 14578.7573201559. The cubic root of 212540165 is about 596.7791906559.

Adding to 212540165 its reverse (561045212), we get a palindrome (773585377).

The spelling of 212540165 in words is "two hundred twelve million, five hundred forty thousand, one hundred sixty-five".