11211212111111 has 2 divisors, whose sum is σ = 11211212111112. Its totient is φ = 11211212111110.

The previous prime is 11211212111093. The next prime is 11211212111131. The reversal of 11211212111111 is 11111121211211.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11211212111111 - 2²² = 11211207916807 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11211212111111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11211212111131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5605606055555 + 5605606055556.

It is an arithmetic number, because the mean of its divisors is an integer number (5605606055556).

Almost surely, 2^{11211212111111} is an apocalyptic number.

11211212111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

11211212111111 is an equidigital number, since it uses as much as digits as its factorization.

11211212111111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8, while the sum is 17.

Adding to 11211212111111 its reverse (11111121211211), we get a palindrome (22322333322322).

The spelling of 11211212111111 in words is "eleven trillion, two hundred eleven billion, two hundred twelve million, one hundred eleven thousand, one hundred eleven".