31271304221 has 2 divisors, whose sum is σ = 31271304222. Its totient is φ = 31271304220.

The previous prime is 31271304193. The next prime is 31271304247. The reversal of 31271304221 is 12240317213.

It is an a-pointer prime, because the next prime (31271304247) can be obtained adding 31271304221 to its sum of digits (26).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30024225625 + 1247078596 = 173275^2 + 35314^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31271304221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31271309221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15635652110 + 15635652111.

It is an arithmetic number, because the mean of its divisors is an integer number (15635652111).

Almost surely, 2^31271304221 is an apocalyptic number.

It is an amenable number.

31271304221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31271304221 is an equidigital number, since it uses as much as digits as its factorization.

31271304221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The spelling of 31271304221 in words is "thirty-one billion, two hundred seventy-one million, three hundred four thousand, two hundred twenty-one".