31313143231 has 4 divisors (see below), whose sum is σ = 31319139112. Its totient is φ = 31307147352.

The previous prime is 31313143229. The next prime is 31313143247. The reversal of 31313143231 is 13234131313.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31313143231 - 2¹ = 31313143229 is a prime.

It is a super-2 number, since 2×31313143231² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31313143196 and 31313143205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31313143271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2990100 + ... + 3000553.

It is an arithmetic number, because the mean of its divisors is an integer number (7829784778).

Almost surely, 2^31313143231 is an apocalyptic number.

31313143231 is a deficient number, since it is larger than the sum of its proper divisors (5995881).

31313143231 is an equidigital number, since it uses as much as digits as its factorization.

31313143231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5995880.

The product of its digits is 1944, while the sum is 25.

Adding to 31313143231 its reverse (13234131313), we get a palindrome (44547274544).

The spelling of 31313143231 in words is "thirty-one billion, three hundred thirteen million, one hundred forty-three thousand, two hundred thirty-one".