2121211111 has 2 divisors, whose sum is σ = 2121211112. Its totient is φ = 2121211110.

The previous prime is 2121211109. The next prime is 2121211139. The reversal of 2121211111 is 1111121212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121211111 - 2¹ = 2121211109 is a prime.

Together with 2121211109, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2121211091 and 2121211100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121211171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060605555 + 1060605556.

It is an arithmetic number, because the mean of its divisors is an integer number (1060605556).

Almost surely, 2^2121211111 is an apocalyptic number.

2121211111 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121211111 is an equidigital number, since it uses as much as digits as its factorization.

2121211111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8, while the sum is 13.

The square root of 2121211111 is about 46056.6076801147. The cubic root of 2121211111 is about 1284.8762387430.

Adding to 2121211111 its reverse (1111121212), we get a palindrome (3232332323).

It can be divided in two parts, 21212 and 11111, that multiplied together give a palindrome (235686532).

The spelling of 2121211111 in words is "two billion, one hundred twenty-one million, two hundred eleven thousand, one hundred eleven".