212621 has 4 divisors (see below), whose sum is σ = 215100. Its totient is φ = 210144.

The previous prime is 212593. The next prime is 212627. The reversal of 212621 is 126212.

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 44521 + 168100 = 211^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 212621 - 2⁶ = 212557 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212596 and 212605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1106 + ... + 1283.

It is an arithmetic number, because the mean of its divisors is an integer number (53775).

2²¹²⁶²¹ is an apocalyptic number.

It is an amenable number.

212621 is a deficient number, since it is larger than the sum of its proper divisors (2479).

212621 is an equidigital number, since it uses as much as digits as its factorization.

212621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2478.

The product of its digits is 48, while the sum is 14.

The square root of 212621 is about 461.1084471141. The cubic root of 212621 is about 59.6854838368.

Adding to 212621 its reverse (126212), we get a palindrome (338833).

The spelling of 212621 in words is "two hundred twelve thousand, six hundred twenty-one".