21100220111 has 2 divisors, whose sum is σ = 21100220112. Its totient is φ = 21100220110.

The previous prime is 21100220101. The next prime is 21100220131. The reversal of 21100220111 is 11102200112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21100220111 - 2¹⁰ = 21100219087 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21100220092 and 21100220101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100220101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550110055 + 10550110056.

It is an arithmetic number, because the mean of its divisors is an integer number (10550110056).

Almost surely, 2^21100220111 is an apocalyptic number.

21100220111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100220111 is an equidigital number, since it uses as much as digits as its factorization.

21100220111 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 11.

Adding to 21100220111 its reverse (11102200112), we get a palindrome (32202420223).

The spelling of 21100220111 in words is "twenty-one billion, one hundred million, two hundred twenty thousand, one hundred eleven".