212210121222221 has 4 divisors (see below), whose sum is σ = 212210477352000. Its totient is φ = 212209765092444.

The previous prime is 212210121222199. The next prime is 212210121222233. The reversal of 212210121222221 is 122222121012212.

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 212210121222221 - 2²² = 212210117027917 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 (212210121222251) 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, 177169571 + ... + 178363328.

It is an arithmetic number, because the mean of its divisors is an integer number (53052619338000).

Almost surely, 2^{212210121222221} is an apocalyptic number.

It is an amenable number.

212210121222221 is a deficient number, since it is larger than the sum of its proper divisors (356129779).

212210121222221 is an equidigital number, since it uses as much as digits as its factorization.

212210121222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356129778.

The product of its (nonzero) digits is 512, while the sum is 23.

Adding to 212210121222221 its reverse (122222121012212), we get a palindrome (334432242234433).

The spelling of 212210121222221 in words is "two hundred twelve trillion, two hundred ten billion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".