20121331313 has 2 divisors, whose sum is σ = 20121331314. Its totient is φ = 20121331312.

The previous prime is 20121331289. The next prime is 20121331331. The reversal of 20121331313 is 31313312102.

Together with next prime (20121331331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13392738529 + 6728592784 = 115727^2 + 82028^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121331313 - 2⁶ = 20121331249 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121331513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060665656 + 10060665657.

It is an arithmetic number, because the mean of its divisors is an integer number (10060665657).

Almost surely, 2^20121331313 is an apocalyptic number.

It is an amenable number.

20121331313 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121331313 is an equidigital number, since it uses as much as digits as its factorization.

20121331313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 20121331313 its reverse (31313312102), we get a palindrome (51434643415).

The spelling of 20121331313 in words is "twenty billion, one hundred twenty-one million, three hundred thirty-one thousand, three hundred thirteen".