21011011213 has 2 divisors, whose sum is σ = 21011011214. Its totient is φ = 21011011212.

The previous prime is 21011011201. The next prime is 21011011223. The reversal of 21011011213 is 31211011012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13327086249 + 7683924964 = 115443^2 + 87658^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011011213 - 2⁹ = 21011010701 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011011193 and 21011011202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011011223) 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, 10505505606 + 10505505607.

It is an arithmetic number, because the mean of its divisors is an integer number (10505505607).

Almost surely, 2^21011011213 is an apocalyptic number.

It is an amenable number.

21011011213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011011213 is an equidigital number, since it uses as much as digits as its factorization.

21011011213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21011011213 its reverse (31211011012), we get a palindrome (52222022225).

The spelling of 21011011213 in words is "twenty-one billion, eleven million, eleven thousand, two hundred thirteen".