21011113013021 has 2 divisors, whose sum is σ = 21011113013022. Its totient is φ = 21011113013020.

The previous prime is 21011113013017. The next prime is 21011113013039. The reversal of 21011113013021 is 12031031111012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11997487860121 + 9013625152900 = 3463739^2 + 3002270^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011113013021 - 2² = 21011113013017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011163013021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505556506510 + 10505556506511.

It is an arithmetic number, because the mean of its divisors is an integer number (10505556506511).

Almost surely, 2^{21011113013021} is an apocalyptic number.

It is an amenable number.

21011113013021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011113013021 is an equidigital number, since it uses as much as digits as its factorization.

21011113013021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 17.

Adding to 21011113013021 its reverse (12031031111012), we get a palindrome (33042144124033).

The spelling of 21011113013021 in words is "twenty-one trillion, eleven billion, one hundred thirteen million, thirteen thousand, twenty-one".