20102111111 has 2 divisors, whose sum is σ = 20102111112. Its totient is φ = 20102111110.

The previous prime is 20102111069. The next prime is 20102111129. The reversal of 20102111111 is 11111120102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20102111111 - 2¹⁰ = 20102110087 is a prime.

It is a super-2 number, since 2×20102111111² (a number of 21 digits) contains 22 as substring.

20102111111 is a modest number, since divided by 111111 gives 20102 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 20102111092 and 20102111101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20102111311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10051055555 + 10051055556.

It is an arithmetic number, because the mean of its divisors is an integer number (10051055556).

Almost surely, 2^20102111111 is an apocalyptic number.

20102111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20102111111 is an equidigital number, since it uses as much as digits as its factorization.

20102111111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 20102111111 its reverse (11111120102), we get a palindrome (31213231213).

It can be divided in two parts, 20102 and 111111, that multiplied together give a palindrome (2233553322).

The spelling of 20102111111 in words is "twenty billion, one hundred two million, one hundred eleven thousand, one hundred eleven".