31112213022221 has 2 divisors, whose sum is σ = 31112213022222. Its totient is φ = 31112213022220.

The previous prime is 31112213022217. The next prime is 31112213022349. The reversal of 31112213022221 is 12222031221113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28591628128996 + 2520584893225 = 5347114^2 + 1587635^2 .

It is a cyclic number.

It is not a de Polignac number, because 31112213022221 - 2² = 31112213022217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31112213021221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15556106511110 + 15556106511111.

It is an arithmetic number, because the mean of its divisors is an integer number (15556106511111).

Almost surely, 2^{31112213022221} is an apocalyptic number.

It is an amenable number.

31112213022221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31112213022221 is an equidigital number, since it uses as much as digits as its factorization.

31112213022221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 31112213022221 its reverse (12222031221113), we get a palindrome (43334244243334).

The spelling of 31112213022221 in words is "thirty-one trillion, one hundred twelve billion, two hundred thirteen million, twenty-two thousand, two hundred twenty-one".