3121111111 has 2 divisors, whose sum is σ = 3121111112. Its totient is φ = 3121111110.

The previous prime is 3121111013. The next prime is 3121111139. The reversal of 3121111111 is 1111111213.

It is a strong prime.

It is an emirp because it is prime and its reverse (1111111213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3121111111 - 2¹⁹ = 3120586823 is a prime.

3121111111 is a modest number, since divided by 111111 gives 3121 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 3121111091 and 3121111100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3121111181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1560555555 + 1560555556.

It is an arithmetic number, because the mean of its divisors is an integer number (1560555556).

Almost surely, 2^3121111111 is an apocalyptic number.

3121111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121111111 is an equidigital number, since it uses as much as digits as its factorization.

3121111111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6, while the sum is 13.

The square root of 3121111111 is about 55866.9053286469. The cubic root of 3121111111 is about 1461.4021544069.

Adding to 3121111111 its reverse (1111111213), we get a palindrome (4232222324).

The spelling of 3121111111 in words is "three billion, one hundred twenty-one million, one hundred eleven thousand, one hundred eleven".