21220444111 has 2 divisors, whose sum is σ = 21220444112. Its totient is φ = 21220444110.

The previous prime is 21220444067. The next prime is 21220444121. The reversal of 21220444111 is 11144402212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21220444111 - 2⁹ = 21220443599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220444121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610222055 + 10610222056.

It is an arithmetic number, because the mean of its divisors is an integer number (10610222056).

Almost surely, 2^21220444111 is an apocalyptic number.

21220444111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220444111 is an equidigital number, since it uses as much as digits as its factorization.

21220444111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 21220444111 its reverse (11144402212), we get a palindrome (32364846323).

The spelling of 21220444111 in words is "twenty-one billion, two hundred twenty million, four hundred forty-four thousand, one hundred eleven".