2161231111111 has 2 divisors, whose sum is σ = 2161231111112. Its totient is φ = 2161231111110.

The previous prime is 2161231111099. The next prime is 2161231111183. The reversal of 2161231111111 is 1111111321612.

It is a m-pointer prime, because the next prime (2161231111183) can be obtained adding 2161231111111 to its product of digits (72).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2161231111111 - 2¹⁷ = 2161230980039 is a prime.

2161231111111 is a modest number, since divided by 1111111 gives 216123 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161231114111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080615555555 + 1080615555556.

It is an arithmetic number, because the mean of its divisors is an integer number (1080615555556).

Almost surely, 2^{2161231111111} is an apocalyptic number.

2161231111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161231111111 is an equidigital number, since it uses as much as digits as its factorization.

2161231111111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 22.

Adding to 2161231111111 its reverse (1111111321612), we get a palindrome (3272342432723).

The spelling of 2161231111111 in words is "two trillion, one hundred sixty-one billion, two hundred thirty-one million, one hundred eleven thousand, one hundred eleven".