31131321442 has 16 divisors (see below), whose sum is σ = 51648223032. Its totient is φ = 13979969280.

The previous prime is 31131321437. The next prime is 31131321449. The reversal of 31131321442 is 24412313113.

It can be written as a sum of positive squares in 4 ways, for example, as 18947797801 + 12183523641 = 137651^2 + 110379^2 .

It is not an unprimeable number, because it can be changed into a prime (31131321449) 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 7 ways as a sum of consecutive naturals, for example, 16179559 + ... + 16181482.

Almost surely, 2^31131321442 is an apocalyptic number.

31131321442 is a deficient number, since it is larger than the sum of its proper divisors (20516901590).

31131321442 is a wasteful number, since it uses less digits than its factorization.

31131321442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32361093.

The product of its digits is 1728, while the sum is 25.

Adding to 31131321442 its reverse (24412313113), we get a palindrome (55543634555).

The spelling of 31131321442 in words is "thirty-one billion, one hundred thirty-one million, three hundred twenty-one thousand, four hundred forty-two".