1211213111 has 2 divisors, whose sum is σ = 1211213112. Its totient is φ = 1211213110.

The previous prime is 1211213071. The next prime is 1211213117. The reversal of 1211213111 is 1113121121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211213111 - 2¹⁸ = 1210950967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211213117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605606555 + 605606556.

It is an arithmetic number, because the mean of its divisors is an integer number (605606556).

Almost surely, 2^1211213111 is an apocalyptic number.

1211213111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211213111 is an equidigital number, since it uses as much as digits as its factorization.

1211213111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12, while the sum is 14.

The square root of 1211213111 is about 34802.4871381343. The cubic root of 1211213111 is about 1065.9582318161.

Adding to 1211213111 its reverse (1113121121), we get a palindrome (2324334232).

The spelling of 1211213111 in words is "one billion, two hundred eleven million, two hundred thirteen thousand, one hundred eleven".