1212121222111 has 6 divisors (see below), whose sum is σ = 1227658754112. Its totient is φ = 1196777909340.

The previous prime is 1212121222099. The next prime is 1212121222159. The reversal of 1212121222111 is 1112221212121.

It is a happy number.

It is not a de Polignac number, because 1212121222111 - 2¹⁵ = 1212121189343 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 (1212121222811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 97103295 + ... + 97115776.

It is an arithmetic number, because the mean of its divisors is an integer number (204609792352).

Almost surely, 2^{1212121222111} is an apocalyptic number.

1212121222111 is a deficient number, since it is larger than the sum of its proper divisors (15537532001).

1212121222111 is an frugal number, since it uses more digits than its factorization.

1212121222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194219229 (or 194219150 counting only the distinct ones).

The product of its digits is 64, while the sum is 19.

Adding to 1212121222111 its reverse (1112221212121), we get a palindrome (2324342434232).

The spelling of 1212121222111 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred eleven".