1212122221221 has 16 divisors (see below), whose sum is σ = 1661130936000. Its totient is φ = 785631385728.

The previous prime is 1212122221213. The next prime is 1212122221223. The reversal of 1212122221221 is 1221222212121.

It is not a de Polignac number, because 1212122221221 - 2³ = 1212122221213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212122221223) 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, 4092771 + ... + 4378928.

It is an arithmetic number, because the mean of its divisors is an integer number (103820683500).

Almost surely, 2^{1212122221221} is an apocalyptic number.

It is an amenable number.

1212122221221 is a deficient number, since it is larger than the sum of its proper divisors (449008714779).

1212122221221 is a wasteful number, since it uses less digits than its factorization.

1212122221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8473028.

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

Adding to 1212122221221 its reverse (1221222212121), we get a palindrome (2433344433342).

The spelling of 1212122221221 in words is "one trillion, two hundred twelve billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred twenty-one".