21111100101211 has 2 divisors, whose sum is σ = 21111100101212. Its totient is φ = 21111100101210.

The previous prime is 21111100101209. The next prime is 21111100101233. The reversal of 21111100101211 is 11210100111112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21111100101211 - 2¹ = 21111100101209 is a prime.

Together with 21111100101209, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21111100101191 and 21111100101200.

It is not a weakly prime, because it can be changed into another prime (21111100101811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555550050605 + 10555550050606.

It is an arithmetic number, because the mean of its divisors is an integer number (10555550050606).

Almost surely, 2^{21111100101211} is an apocalyptic number.

21111100101211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111100101211 is an equidigital number, since it uses as much as digits as its factorization.

21111100101211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21111100101211 its reverse (11210100111112), we get a palindrome (32321200212323).

Subtracting from 21111100101211 its reverse (11210100111112), we obtain a palindrome (9900999990099).

The spelling of 21111100101211 in words is "twenty-one trillion, one hundred eleven billion, one hundred million, one hundred one thousand, two hundred eleven".