31313302021 has 2 divisors, whose sum is σ = 31313302022. Its totient is φ = 31313302020.

The previous prime is 31313302019. The next prime is 31313302079. The reversal of 31313302021 is 12020331313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15835453921 + 15477848100 = 125839^2 + 124410^2 .

It is a cyclic number.

It is not a de Polignac number, because 31313302021 - 2¹ = 31313302019 is a prime.

Together with 31313302019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 31313302021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31313332021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656651010 + 15656651011.

It is an arithmetic number, because the mean of its divisors is an integer number (15656651011).

Almost surely, 2^31313302021 is an apocalyptic number.

It is an amenable number.

31313302021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31313302021 is an equidigital number, since it uses as much as digits as its factorization.

31313302021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 31313302021 its reverse (12020331313), we get a palindrome (43333633334).

The spelling of 31313302021 in words is "thirty-one billion, three hundred thirteen million, three hundred two thousand, twenty-one".