31221312012013 has 2 divisors, whose sum is σ = 31221312012014. Its totient is φ = 31221312012012.

The previous prime is 31221312011951. The next prime is 31221312012029. The reversal of 31221312012013 is 31021021312213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28103537830729 + 3117774181284 = 5301277^2 + 1765722^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31221312012013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31221312012043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610656006006 + 15610656006007.

It is an arithmetic number, because the mean of its divisors is an integer number (15610656006007).

Almost surely, 2^{31221312012013} is an apocalyptic number.

It is an amenable number.

31221312012013 is a deficient number, since it is larger than the sum of its proper divisors (1).

31221312012013 is an equidigital number, since it uses as much as digits as its factorization.

31221312012013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 31221312012013 its reverse (31021021312213), we get a palindrome (62242333324226).

The spelling of 31221312012013 in words is "thirty-one trillion, two hundred twenty-one billion, three hundred twelve million, twelve thousand, thirteen".