21330111211 has 2 divisors, whose sum is σ = 21330111212. Its totient is φ = 21330111210.

The previous prime is 21330111203. The next prime is 21330111221. The reversal of 21330111211 is 11211103312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21330111211 - 2³ = 21330111203 is a prime.

It is not a weakly prime, because it can be changed into another prime (21330111221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665055605 + 10665055606.

It is an arithmetic number, because the mean of its divisors is an integer number (10665055606).

Almost surely, 2^21330111211 is an apocalyptic number.

21330111211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21330111211 is an equidigital number, since it uses as much as digits as its factorization.

21330111211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21330111211 its reverse (11211103312), we get a palindrome (32541214523).

The spelling of 21330111211 in words is "twenty-one billion, three hundred thirty million, one hundred eleven thousand, two hundred eleven".