212521 has 3 divisors (see below), whose sum is σ = 212983. Its totient is φ = 212060.

The previous prime is 212507. The next prime is 212557. The reversal of 212521 is 125212.

212521 = T₄₆₀ + T₄₆₁.

The square root of 212521 is 461.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 68121 + 144400 = 261^2 + 380^2 .

It is not a de Polignac number, because 212521 - 2¹³ = 204329 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212501) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 231 + ... + 691.

2²¹²⁵²¹ is an apocalyptic number.

212521 is the 461-st square number.

212521 is the 231-st centered octagonal number.

It is an amenable number.

212521 is a deficient number, since it is larger than the sum of its proper divisors (462).

212521 is an frugal number, since it uses more digits than its factorization.

212521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 922 (or 461 counting only the distinct ones).

The product of its digits is 40, while the sum is 13.

The cubic root of 212521 is about 59.6761252686.

Adding to 212521 its reverse (125212), we get a palindrome (337733).

The spelling of 212521 in words is "two hundred twelve thousand, five hundred twenty-one".