212102521 has 4 divisors (see below), whose sum is σ = 212703732. Its totient is φ = 211501312.

The previous prime is 212102519. The next prime is 212102563. The reversal of 212102521 is 125201212.

It is a happy number.

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 142563600 + 69538921 = 11940^2 + 8339^2 .

It is a cyclic number.

It is not a de Polignac number, because 212102521 - 2¹ = 212102519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212102495 and 212102504.

It is not an unprimeable number, because it can be changed into a prime (212102221) 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, 300076 + ... + 300781.

It is an arithmetic number, because the mean of its divisors is an integer number (53175933).

Almost surely, 2^212102521 is an apocalyptic number.

It is an amenable number.

212102521 is a deficient number, since it is larger than the sum of its proper divisors (601211).

212102521 is an equidigital number, since it uses as much as digits as its factorization.

212102521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601210.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 212102521 is about 14563.7399386284. The cubic root of 212102521 is about 596.3692974614.

Adding to 212102521 its reverse (125201212), we get a palindrome (337303733).

The spelling of 212102521 in words is "two hundred twelve million, one hundred two thousand, five hundred twenty-one".