21010211111243 has 2 divisors, whose sum is σ = 21010211111244. Its totient is φ = 21010211111242.

The previous prime is 21010211111179. The next prime is 21010211111293. The reversal of 21010211111243 is 34211111201012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21010211111243 - 2⁶ = 21010211111179 is a prime.

It is not a weakly prime, because it can be changed into another prime (21010211111293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505105555621 + 10505105555622.

It is an arithmetic number, because the mean of its divisors is an integer number (10505105555622).

Almost surely, 2^{21010211111243} is an apocalyptic number.

21010211111243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010211111243 is an equidigital number, since it uses as much as digits as its factorization.

21010211111243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 21010211111243 its reverse (34211111201012), we get a palindrome (55221322312255).

The spelling of 21010211111243 in words is "twenty-one trillion, ten billion, two hundred eleven million, one hundred eleven thousand, two hundred forty-three".