212102211221 has 4 divisors (see below), whose sum is σ = 212103432672. Its totient is φ = 212100989772.

The previous prime is 212102211199. The next prime is 212102211253. The reversal of 212102211221 is 122112201212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212102211221 - 2¹⁰ = 212102210197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212102211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212102211421) 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, 296291 + ... + 715536.

It is an arithmetic number, because the mean of its divisors is an integer number (53025858168).

Almost surely, 2^212102211221 is an apocalyptic number.

It is an amenable number.

212102211221 is a deficient number, since it is larger than the sum of its proper divisors (1221451).

212102211221 is a wasteful number, since it uses less digits than its factorization.

212102211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1221450.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 212102211221 its reverse (122112201212), we get a palindrome (334214412433).

The spelling of 212102211221 in words is "two hundred twelve billion, one hundred two million, two hundred eleven thousand, two hundred twenty-one".