21311331201313 has 2 divisors, whose sum is σ = 21311331201314. Its totient is φ = 21311331201312.

The previous prime is 21311331201299. The next prime is 21311331201331. The reversal of 21311331201313 is 31310213311312.

Together with next prime (21311331201331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16071182996544 + 5240148204769 = 4008888^2 + 2289137^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311331201313 - 2¹³ = 21311331193121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21311331201383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655665600656 + 10655665600657.

It is an arithmetic number, because the mean of its divisors is an integer number (10655665600657).

Almost surely, 2^{21311331201313} is an apocalyptic number.

It is an amenable number.

21311331201313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311331201313 is an equidigital number, since it uses as much as digits as its factorization.

21311331201313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 25.

Adding to 21311331201313 its reverse (31310213311312), we get a palindrome (52621544512625).

The spelling of 21311331201313 in words is "twenty-one trillion, three hundred eleven billion, three hundred thirty-one million, two hundred one thousand, three hundred thirteen".