21103013213 has 2 divisors, whose sum is σ = 21103013214. Its totient is φ = 21103013212.

The previous prime is 21103013209. The next prime is 21103013227. The reversal of 21103013213 is 31231030112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20925936964 + 177076249 = 144658^2 + 13307^2 .

It is a cyclic number.

It is not a de Polignac number, because 21103013213 - 2² = 21103013209 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21103013191 and 21103013200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21103013203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551506606 + 10551506607.

It is an arithmetic number, because the mean of its divisors is an integer number (10551506607).

Almost surely, 2^21103013213 is an apocalyptic number.

It is an amenable number.

21103013213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103013213 is an equidigital number, since it uses as much as digits as its factorization.

21103013213 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 21103013213 its reverse (31231030112), we get a palindrome (52334043325).

The spelling of 21103013213 in words is "twenty-one billion, one hundred three million, thirteen thousand, two hundred thirteen".