31131041231 has 4 divisors (see below), whose sum is σ = 31439269464. Its totient is φ = 30822813000.

The previous prime is 31131041219. The next prime is 31131041233. The reversal of 31131041231 is 13214013113.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31131041231 is a prime.

It is a super-2 number, since 2×31131041231² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31131041233) 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, 154113965 + ... + 154114166.

It is an arithmetic number, because the mean of its divisors is an integer number (7859817366).

Almost surely, 2^31131041231 is an apocalyptic number.

31131041231 is a deficient number, since it is larger than the sum of its proper divisors (308228233).

31131041231 is a wasteful number, since it uses less digits than its factorization.

31131041231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308228232.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 31131041231 its reverse (13214013113), we get a palindrome (44345054344).

The spelling of 31131041231 in words is "thirty-one billion, one hundred thirty-one million, forty-one thousand, two hundred thirty-one".