21331311013 has 2 divisors, whose sum is σ = 21331311014. Its totient is φ = 21331311012.

The previous prime is 21331310941. The next prime is 21331311037. The reversal of 21331311013 is 31011313312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21325637089 + 5673924 = 146033^2 + 2382^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331311013 - 2⁹ = 21331310501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21331311073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665655506 + 10665655507.

It is an arithmetic number, because the mean of its divisors is an integer number (10665655507).

Almost surely, 2^21331311013 is an apocalyptic number.

It is an amenable number.

21331311013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331311013 is an equidigital number, since it uses as much as digits as its factorization.

21331311013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 19.

Adding to 21331311013 its reverse (31011313312), we get a palindrome (52342624325).

The spelling of 21331311013 in words is "twenty-one billion, three hundred thirty-one million, three hundred eleven thousand, thirteen".