212221112021 has 4 divisors (see below), whose sum is σ = 212222077932. Its totient is φ = 212220146112.

The previous prime is 212221112017. The next prime is 212221112039. The reversal of 212221112021 is 120211122212.

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 2 ways, for example, as 64496189521 + 147724922500 = 253961^2 + 384350^2 .

It is a cyclic number.

It is not a de Polignac number, because 212221112021 - 2² = 212221112017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212221117021) 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, 23981 + ... + 651933.

It is an arithmetic number, because the mean of its divisors is an integer number (53055519483).

Almost surely, 2^212221112021 is an apocalyptic number.

It is an amenable number.

212221112021 is a deficient number, since it is larger than the sum of its proper divisors (965911).

212221112021 is an equidigital number, since it uses as much as digits as its factorization.

212221112021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965910.

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

Adding to 212221112021 its reverse (120211122212), we get a palindrome (332432234233).

The spelling of 212221112021 in words is "two hundred twelve billion, two hundred twenty-one million, one hundred twelve thousand, twenty-one".