1212221212221 has 16 divisors (see below), whose sum is σ = 1618595596800. Its totient is φ = 806997600048.

The previous prime is 1212221212199. The next prime is 1212221212247. The reversal of 1212221212221 is 1222121222121.

It is not a de Polignac number, because 1212221212221 - 2⁶ = 1212221212157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212221212421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11290690 + ... + 11397548.

It is an arithmetic number, because the mean of its divisors is an integer number (101162224800).

Almost surely, 2^{1212221212221} is an apocalyptic number.

It is an amenable number.

1212221212221 is a deficient number, since it is larger than the sum of its proper divisors (406374384579).

1212221212221 is a wasteful number, since it uses less digits than its factorization.

1212221212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112208.

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

Adding to 1212221212221 its reverse (1222121222121), we get a palindrome (2434342434342).

The spelling of 1212221212221 in words is "one trillion, two hundred twelve billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".