1221211202111 has 2 divisors, whose sum is σ = 1221211202112. Its totient is φ = 1221211202110.

The previous prime is 1221211202093. The next prime is 1221211202191. The reversal of 1221211202111 is 1112021121221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221211202111 - 2¹⁸ = 1221210939967 is a prime.

It is a super-2 number, since 2×1221211202111² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221211202111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221211202191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610605601055 + 610605601056.

It is an arithmetic number, because the mean of its divisors is an integer number (610605601056).

Almost surely, 2^{1221211202111} is an apocalyptic number.

1221211202111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221211202111 is an equidigital number, since it uses as much as digits as its factorization.

1221211202111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221211202111 its reverse (1112021121221), we get a palindrome (2333232323332).

The spelling of 1221211202111 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred two thousand, one hundred eleven".