31121222131 has 2 divisors, whose sum is σ = 31121222132. Its totient is φ = 31121222130.

The previous prime is 31121222123. The next prime is 31121222137. The reversal of 31121222131 is 13122212113.

It is a strong prime.

It is an emirp because it is prime and its reverse (13122212113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31121222131 - 2³ = 31121222123 is a prime.

It is a super-2 number, since 2×31121222131² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31121222099 and 31121222108.

It is not a weakly prime, because it can be changed into another prime (31121222137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560611065 + 15560611066.

It is an arithmetic number, because the mean of its divisors is an integer number (15560611066).

Almost surely, 2^31121222131 is an apocalyptic number.

31121222131 is a deficient number, since it is larger than the sum of its proper divisors (1).

31121222131 is an equidigital number, since it uses as much as digits as its factorization.

31121222131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 19.

Adding to 31121222131 its reverse (13122212113), we get a palindrome (44243434244).

The spelling of 31121222131 in words is "thirty-one billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred thirty-one".