21110211211 has 2 divisors, whose sum is σ = 21110211212. Its totient is φ = 21110211210.

The previous prime is 21110211209. The next prime is 21110211217. The reversal of 21110211211 is 11211201112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21110211211 - 2¹ = 21110211209 is a prime.

Together with 21110211209, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21110211191 and 21110211200.

It is not a weakly prime, because it can be changed into another prime (21110211217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555105605 + 10555105606.

It is an arithmetic number, because the mean of its divisors is an integer number (10555105606).

Almost surely, 2^21110211211 is an apocalyptic number.

21110211211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110211211 is an equidigital number, since it uses as much as digits as its factorization.

21110211211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21110211211 its reverse (11211201112), we get a palindrome (32321412323).

The spelling of 21110211211 in words is "twenty-one billion, one hundred ten million, two hundred eleven thousand, two hundred eleven".