31303220221 has 12 divisors (see below), whose sum is σ = 39215023932. Its totient is φ = 24767382528.

The previous prime is 31303220219. The next prime is 31303220231. The reversal of 31303220221 is 12202230313.

It can be written as a sum of positive squares in 2 ways, for example, as 15955479225 + 15347740996 = 126315^2 + 123886^2 .

It is not a de Polignac number, because 31303220221 - 2¹ = 31303220219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31303220231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24570180 + ... + 24571453.

It is an arithmetic number, because the mean of its divisors is an integer number (3267918661).

Almost surely, 2^31303220221 is an apocalyptic number.

It is an amenable number.

31303220221 is a deficient number, since it is larger than the sum of its proper divisors (7911803711).

31303220221 is a wasteful number, since it uses less digits than its factorization.

31303220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49141660 (or 49141653 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 31303220221 its reverse (12202230313), we get a palindrome (43505450534).

The spelling of 31303220221 in words is "thirty-one billion, three hundred three million, two hundred twenty thousand, two hundred twenty-one".