31303223318221 has 2 divisors, whose sum is σ = 31303223318222. Its totient is φ = 31303223318220.

The previous prime is 31303223318167. The next prime is 31303223318249. The reversal of 31303223318221 is 12281332230313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31071549562596 + 231673755625 = 5574186^2 + 481325^2 .

It is a cyclic number.

It is not a de Polignac number, because 31303223318221 - 2¹¹ = 31303223316173 is a prime.

It is a super-2 number, since 2×31303223318221² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31303223318261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15651611659110 + 15651611659111.

It is an arithmetic number, because the mean of its divisors is an integer number (15651611659111).

Almost surely, 2^{31303223318221} is an apocalyptic number.

It is an amenable number.

31303223318221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31303223318221 is an equidigital number, since it uses as much as digits as its factorization.

31303223318221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 34.

Adding to 31303223318221 its reverse (12281332230313), we get a palindrome (43584555548534).

The spelling of 31303223318221 in words is "thirty-one trillion, three hundred three billion, two hundred twenty-three million, three hundred eighteen thousand, two hundred twenty-one".