20131123231 has 2 divisors, whose sum is σ = 20131123232. Its totient is φ = 20131123230.

The previous prime is 20131123211. The next prime is 20131123249. The reversal of 20131123231 is 13232113102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20131123231 is a prime.

It is a super-2 number, since 2×20131123231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20131123199 and 20131123208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20131123211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065561615 + 10065561616.

It is an arithmetic number, because the mean of its divisors is an integer number (10065561616).

Almost surely, 2^20131123231 is an apocalyptic number.

20131123231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131123231 is an equidigital number, since it uses as much as digits as its factorization.

20131123231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 20131123231 its reverse (13232113102), we get a palindrome (33363236333).

The spelling of 20131123231 in words is "twenty billion, one hundred thirty-one million, one hundred twenty-three thousand, two hundred thirty-one".