20131131111 has 48 divisors (see below), whose sum is σ = 35171276544. Its totient is φ = 9993964032.

The previous prime is 20131131107. The next prime is 20131131127. The reversal of 20131131111 is 11113113102.

It is not a de Polignac number, because 20131131111 - 2² = 20131131107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131131101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 106501 + ... + 227166.

It is an arithmetic number, because the mean of its divisors is an integer number (732734928).

Almost surely, 2^20131131111 is an apocalyptic number.

20131131111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20131131111 is a deficient number, since it is larger than the sum of its proper divisors (15040145433).

20131131111 is a wasteful number, since it uses less digits than its factorization.

20131131111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333720 (or 333707 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 15.

Adding to 20131131111 its reverse (11113113102), we get a palindrome (31244244213).

It can be divided in two parts, 20 and 131131111, that added together give a palindrome (131131131).

The spelling of 20131131111 in words is "twenty billion, one hundred thirty-one million, one hundred thirty-one thousand, one hundred eleven".