20012131111 has 24 divisors (see below), whose sum is σ = 25720506720. Its totient is φ = 15442301952.

The previous prime is 20012131109. The next prime is 20012131129. The reversal of 20012131111 is 11113121002.

It is a happy number.

It is not a de Polignac number, because 20012131111 - 2¹ = 20012131109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20012131091 and 20012131100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20012131171) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 503106 + ... + 541423.

It is an arithmetic number, because the mean of its divisors is an integer number (1071687780).

Almost surely, 2^20012131111 is an apocalyptic number.

20012131111 is a deficient number, since it is larger than the sum of its proper divisors (5708375609).

20012131111 is a wasteful number, since it uses less digits than its factorization.

20012131111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044583 (or 1044576 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 20012131111 its reverse (11113121002), we get a palindrome (31125252113).

The spelling of 20012131111 in words is "twenty billion, twelve million, one hundred thirty-one thousand, one hundred eleven".