123111011111 has 64 divisors (see below), whose sum is σ = 151135497216. Its totient is φ = 98902425600.

The previous prime is 123111011099. The next prime is 123111011131. The reversal of 123111011111 is 111110111321.

It is a de Polignac number, because none of the positive numbers 2^k-123111011111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123111011131) 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 63 ways as a sum of consecutive naturals, for example, 75666680 + ... + 75668306.

It is an arithmetic number, because the mean of its divisors is an integer number (2361492144).

Almost surely, 2^123111011111 is an apocalyptic number.

123111011111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

123111011111 is a deficient number, since it is larger than the sum of its proper divisors (28024486105).

123111011111 is a wasteful number, since it uses less digits than its factorization.

123111011111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992.

The product of its (nonzero) digits is 6, while the sum is 14.

Adding to 123111011111 its reverse (111110111321), we get a palindrome (234221122432).

The spelling of 123111011111 in words is "one hundred twenty-three billion, one hundred eleven million, eleven thousand, one hundred eleven".