21441211111 has 4 divisors (see below), whose sum is σ = 21510154224. Its totient is φ = 21372268000.

The previous prime is 21441211093. The next prime is 21441211153. The reversal of 21441211111 is 11111214412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21441211111 - 2⁵ = 21441211079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21441218111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34471090 + ... + 34471711.

It is an arithmetic number, because the mean of its divisors is an integer number (5377538556).

Almost surely, 2^21441211111 is an apocalyptic number.

21441211111 is a deficient number, since it is larger than the sum of its proper divisors (68943113).

21441211111 is an equidigital number, since it uses as much as digits as its factorization.

21441211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68943112.

The product of its digits is 64, while the sum is 19.

Adding to 21441211111 its reverse (11111214412), we get a palindrome (32552425523).

The spelling of 21441211111 in words is "twenty-one billion, four hundred forty-one million, two hundred eleven thousand, one hundred eleven".