20123111121111 has 32 divisors (see below), whose sum is σ = 30180743562240. Its totient is φ = 13415106259800.

The previous prime is 20123111121101. The next prime is 20123111121119. The reversal of 20123111121111 is 11112111132102.

20123111121111 is a `hidden beast` number, since 201 + 231 + 1 + 1 + 121 + 111 = 666.

It is not a de Polignac number, because 20123111121111 - 2¹⁸ = 20123110858967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123111121119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142090786 + ... + 142232336.

It is an arithmetic number, because the mean of its divisors is an integer number (943148236320).

Almost surely, 2^{20123111121111} is an apocalyptic number.

20123111121111 is a deficient number, since it is larger than the sum of its proper divisors (10057632441129).

20123111121111 is an frugal number, since it uses more digits than its factorization.

20123111121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206575 (or 206557 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 18.

Adding to 20123111121111 its reverse (11112111132102), we get a palindrome (31235222253213).

The spelling of 20123111121111 in words is "twenty trillion, one hundred twenty-three billion, one hundred eleven million, one hundred twenty-one thousand, one hundred eleven".