212100221122221 has 4 divisors (see below), whose sum is σ = 282800294829632. Its totient is φ = 141400147414812.

The previous prime is 212100221122213. The next prime is 212100221122291. The reversal of 212100221122221 is 122221122001212.

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 not a de Polignac number, because 212100221122221 - 2³ = 212100221122213 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 (212100221122211) 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, 35350036853701 + ... + 35350036853706.

It is an arithmetic number, because the mean of its divisors is an integer number (70700073707408).

Almost surely, 2^{212100221122221} is an apocalyptic number.

It is an amenable number.

212100221122221 is a deficient number, since it is larger than the sum of its proper divisors (70700073707411).

212100221122221 is an equidigital number, since it uses as much as digits as its factorization.

212100221122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70700073707410.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 212100221122221 its reverse (122221122001212), we get a palindrome (334321343123433).

The spelling of 212100221122221 in words is "two hundred twelve trillion, one hundred billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".