21013103213 has 2 divisors, whose sum is σ = 21013103214. Its totient is φ = 21013103212.

The previous prime is 21013103203. The next prime is 21013103231. The reversal of 21013103213 is 31230131012.

Together with next prime (21013103231) 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., 17892540169 + 3120563044 = 133763^2 + 55862^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013103213 - 2⁴ = 21013103197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21013103191 and 21013103200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013103203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506551606 + 10506551607.

It is an arithmetic number, because the mean of its divisors is an integer number (10506551607).

Almost surely, 2^21013103213 is an apocalyptic number.

It is an amenable number.

21013103213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013103213 is an equidigital number, since it uses as much as digits as its factorization.

21013103213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21013103213 its reverse (31230131012), we get a palindrome (52243234225).

The spelling of 21013103213 in words is "twenty-one billion, thirteen million, one hundred three thousand, two hundred thirteen".