1212202220221 has 4 divisors (see below), whose sum is σ = 1212221361244. Its totient is φ = 1212183079200.

The previous prime is 1212202220219. The next prime is 1212202220227. The reversal of 1212202220221 is 1220222022121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 675455503321 + 536746716900 = 821861^2 + 732630^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212202220221 - 2¹ = 1212202220219 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 (1212202220227) 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, 9475200 + ... + 9602281.

It is an arithmetic number, because the mean of its divisors is an integer number (303055340311).

Almost surely, 2^{1212202220221} is an apocalyptic number.

It is an amenable number.

1212202220221 is a deficient number, since it is larger than the sum of its proper divisors (19141023).

1212202220221 is an equidigital number, since it uses as much as digits as its factorization.

1212202220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19141022.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 1212202220221 its reverse (1220222022121), we get a palindrome (2432424242342).

The spelling of 1212202220221 in words is "one trillion, two hundred twelve billion, two hundred two million, two hundred twenty thousand, two hundred twenty-one".