212021210022221 has 4 divisors (see below), whose sum is σ = 221239523501472. Its totient is φ = 202802896542972.

The previous prime is 212021210022211. The next prime is 212021210022233. The reversal of 212021210022221 is 122220012120212.

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 212021210022221 - 2¹⁸ = 212021209760077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212021210022193 and 212021210022202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212021210022211) 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, 4609156739591 + ... + 4609156739636.

It is an arithmetic number, because the mean of its divisors is an integer number (55309880875368).

Almost surely, 2^{212021210022221} is an apocalyptic number.

It is an amenable number.

212021210022221 is a deficient number, since it is larger than the sum of its proper divisors (9218313479251).

212021210022221 is an equidigital number, since it uses as much as digits as its factorization.

212021210022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9218313479250.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 212021210022221 its reverse (122220012120212), we get a palindrome (334241222142433).

The spelling of 212021210022221 in words is "two hundred twelve trillion, twenty-one billion, two hundred ten million, twenty-two thousand, two hundred twenty-one".