21015110213 has 2 divisors, whose sum is σ = 21015110214. Its totient is φ = 21015110212.

The previous prime is 21015110153. The next prime is 21015110257. The reversal of 21015110213 is 31201151012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19969363969 + 1045746244 = 141313^2 + 32338^2 .

It is a cyclic number.

It is not a de Polignac number, because 21015110213 - 2⁸ = 21015109957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21015110191 and 21015110200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21015110513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10507555106 + 10507555107.

It is an arithmetic number, because the mean of its divisors is an integer number (10507555107).

Almost surely, 2^21015110213 is an apocalyptic number.

It is an amenable number.

21015110213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21015110213 is an equidigital number, since it uses as much as digits as its factorization.

21015110213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60, while the sum is 17.

Adding to 21015110213 its reverse (31201151012), we get a palindrome (52216261225).

The spelling of 21015110213 in words is "twenty-one billion, fifteen million, one hundred ten thousand, two hundred thirteen".