31303203221 has 2 divisors, whose sum is σ = 31303203222. Its totient is φ = 31303203220.

The previous prime is 31303203199. The next prime is 31303203289. The reversal of 31303203221 is 12230230313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21400764100 + 9902439121 = 146290^2 + 99511^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31303203221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31303203193 and 31303203202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31303200221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15651601610 + 15651601611.

It is an arithmetic number, because the mean of its divisors is an integer number (15651601611).

Almost surely, 2^31303203221 is an apocalyptic number.

It is an amenable number.

31303203221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31303203221 is an equidigital number, since it uses as much as digits as its factorization.

31303203221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 31303203221 its reverse (12230230313), we get a palindrome (43533433534).

The spelling of 31303203221 in words is "thirty-one billion, three hundred three million, two hundred three thousand, two hundred twenty-one".