212010021221 has 4 divisors (see below), whose sum is σ = 214109130444. Its totient is φ = 209910912000.

The previous prime is 212010021217. The next prime is 212010021239. The reversal of 212010021221 is 122120010212.

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 91851424900 + 120158596321 = 303070^2 + 346639^2 .

It is a cyclic number.

It is not a de Polignac number, because 212010021221 - 2² = 212010021217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212010021196 and 212010021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212010021721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1049554460 + ... + 1049554661.

It is an arithmetic number, because the mean of its divisors is an integer number (53527282611).

Almost surely, 2^212010021221 is an apocalyptic number.

It is an amenable number.

212010021221 is a deficient number, since it is larger than the sum of its proper divisors (2099109223).

212010021221 is a wasteful number, since it uses less digits than its factorization.

212010021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2099109222.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 212010021221 its reverse (122120010212), we get a palindrome (334130031433).

The spelling of 212010021221 in words is "two hundred twelve billion, ten million, twenty-one thousand, two hundred twenty-one".