21012301213 has 2 divisors, whose sum is σ = 21012301214. Its totient is φ = 21012301212.

The previous prime is 21012301171. The next prime is 21012301231. The reversal of 21012301213 is 31210321012.

Together with next prime (21012301231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12714366564 + 8297934649 = 112758^2 + 91093^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012301213 - 2²⁵ = 20978746781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012301243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506150606 + 10506150607.

It is an arithmetic number, because the mean of its divisors is an integer number (10506150607).

Almost surely, 2^21012301213 is an apocalyptic number.

It is an amenable number.

21012301213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012301213 is an equidigital number, since it uses as much as digits as its factorization.

21012301213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21012301213 its reverse (31210321012), we get a palindrome (52222622225).

The spelling of 21012301213 in words is "twenty-one billion, twelve million, three hundred one thousand, two hundred thirteen".