31131232321 has 16 divisors (see below), whose sum is σ = 36609408000. Its totient is φ = 25917707088.

The previous prime is 31131232313. The next prime is 31131232351. The reversal of 31131232321 is 12323213113.

It is not a de Polignac number, because 31131232321 - 2³ = 31131232313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31131232292 and 31131232301.

It is not an unprimeable number, because it can be changed into a prime (31131232351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235021 + ... + 342778.

It is an arithmetic number, because the mean of its divisors is an integer number (2288088000).

Almost surely, 2^31131232321 is an apocalyptic number.

It is an amenable number.

31131232321 is a deficient number, since it is larger than the sum of its proper divisors (5478175679).

31131232321 is a wasteful number, since it uses less digits than its factorization.

31131232321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578028.

The product of its digits is 648, while the sum is 22.

Adding to 31131232321 its reverse (12323213113), we get a palindrome (43454445434).

The spelling of 31131232321 in words is "thirty-one billion, one hundred thirty-one million, two hundred thirty-two thousand, three hundred twenty-one".