20123312111 has 6 divisors (see below), whose sum is σ = 23408750880. Its totient is φ = 17248553196.

The previous prime is 20123312089. The next prime is 20123312117. The reversal of 20123312111 is 11121332102.

It is a de Polignac number, because none of the positive numbers 2^k-20123312111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20123312111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123312117) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 205339871 + ... + 205339968.

It is an arithmetic number, because the mean of its divisors is an integer number (3901458480).

Almost surely, 2^20123312111 is an apocalyptic number.

20123312111 is a deficient number, since it is larger than the sum of its proper divisors (3285438769).

20123312111 is an equidigital number, since it uses as much as digits as its factorization.

20123312111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410679853 (or 410679846 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 20123312111 its reverse (11121332102), we get a palindrome (31244644213).

The spelling of 20123312111 in words is "twenty billion, one hundred twenty-three million, three hundred twelve thousand, one hundred eleven".