31112213121 has 24 divisors (see below), whose sum is σ = 49056995520. Its totient is φ = 18843698400.

The previous prime is 31112213113. The next prime is 31112213123. The reversal of 31112213121 is 12131221113.

It is not a de Polignac number, because 31112213121 - 2³ = 31112213113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31112213094 and 31112213103.

It is not an unprimeable number, because it can be changed into a prime (31112213123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 53551 + ... + 255131.

It is an arithmetic number, because the mean of its divisors is an integer number (2044041480).

Almost surely, 2^31112213121 is an apocalyptic number.

It is an amenable number.

31112213121 is a deficient number, since it is larger than the sum of its proper divisors (17944782399).

31112213121 is a wasteful number, since it uses less digits than its factorization.

31112213121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203157 (or 203154 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 31112213121 its reverse (12131221113), we get a palindrome (43243434234).

The spelling of 31112213121 in words is "thirty-one billion, one hundred twelve million, two hundred thirteen thousand, one hundred twenty-one".