21020244111 has 24 divisors (see below), whose sum is σ = 31821110880. Its totient is φ = 13345649856.

The previous prime is 21020244109. The next prime is 21020244169. The reversal of 21020244111 is 11144202012.

21020244111 is a `hidden beast` number, since 2 + 10 + 202 + 441 + 11 = 666.

It is not a de Polignac number, because 21020244111 - 2¹ = 21020244109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020244181) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 174316 + ... + 269121.

It is an arithmetic number, because the mean of its divisors is an integer number (1325879620).

Almost surely, 2^21020244111 is an apocalyptic number.

21020244111 is a deficient number, since it is larger than the sum of its proper divisors (10800866769).

21020244111 is a wasteful number, since it uses less digits than its factorization.

21020244111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443695 (or 443692 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21020244111 its reverse (11144202012), we get a palindrome (32164446123).

The spelling of 21020244111 in words is "twenty-one billion, twenty million, two hundred forty-four thousand, one hundred eleven".