1221112011211 has 2 divisors, whose sum is σ = 1221112011212. Its totient is φ = 1221112011210.

The previous prime is 1221112011193. The next prime is 1221112011283. The reversal of 1221112011211 is 1121102111221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221112011211 - 2¹⁷ = 1221111880139 is a prime.

It is a super-2 number, since 2×1221112011211² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221112011611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610556005605 + 610556005606.

It is an arithmetic number, because the mean of its divisors is an integer number (610556005606).

Almost surely, 2^{1221112011211} is an apocalyptic number.

1221112011211 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221112011211 is an equidigital number, since it uses as much as digits as its factorization.

1221112011211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1221112011211 its reverse (1121102111221), we get a palindrome (2342214122432).

The spelling of 1221112011211 in words is "one trillion, two hundred twenty-one billion, one hundred twelve million, eleven thousand, two hundred eleven".