212120022221 has 4 divisors (see below), whose sum is σ = 212574241152. Its totient is φ = 211665803292.

The previous prime is 212120022211. The next prime is 212120022269. The reversal of 212120022221 is 122220021212.

It is a happy number.

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 212120022221 - 2¹⁸ = 212119760077 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 212120022221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212120022211) 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, 227108765 + ... + 227109698.

It is an arithmetic number, because the mean of its divisors is an integer number (53143560288).

Almost surely, 2^212120022221 is an apocalyptic number.

It is an amenable number.

212120022221 is a deficient number, since it is larger than the sum of its proper divisors (454218931).

212120022221 is an equidigital number, since it uses as much as digits as its factorization.

212120022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454218930.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 212120022221 its reverse (122220021212), we get a palindrome (334340043433).

The spelling of 212120022221 in words is "two hundred twelve billion, one hundred twenty million, twenty-two thousand, two hundred twenty-one".