1221220221212 has 12 divisors (see below), whose sum is σ = 2143477037520. Its totient is φ = 608798210496.

The previous prime is 1221220221157. The next prime is 1221220221239. The reversal of 1221220221212 is 2121220221221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 452973512 + ... + 452976207.

It is an arithmetic number, because the mean of its divisors is an integer number (178623086460).

Almost surely, 2^{1221220221212} is an apocalyptic number.

It is an amenable number.

1221220221212 is a deficient number, since it is larger than the sum of its proper divisors (922256816308).

1221220221212 is a wasteful number, since it uses less digits than its factorization.

1221220221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905950060 (or 905950058 counting only the distinct ones).

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

Adding to 1221220221212 its reverse (2121220221221), we get a palindrome (3342440442433).

Subtracting 1221220221212 from its reverse (2121220221221), we obtain a palindrome (900000000009).

The spelling of 1221220221212 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twelve".