21110221111 has 24 divisors (see below), whose sum is σ = 26740638000. Its totient is φ = 16551005184.

The previous prime is 21110221037. The next prime is 21110221147. The reversal of 21110221111 is 11112201112.

It is a happy number.

It is not a de Polignac number, because 21110221111 - 2⁷ = 21110220983 is a prime.

It is a super-4 number, since 4×21110221111⁴ (a number of 42 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21110221091 and 21110221100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110227111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 363946 + ... + 417943.

It is an arithmetic number, because the mean of its divisors is an integer number (1114193250).

Almost surely, 2^21110221111 is an apocalyptic number.

21110221111 is a deficient number, since it is larger than the sum of its proper divisors (5630416889).

21110221111 is a wasteful number, since it uses less digits than its factorization.

21110221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781951 (or 781944 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21110221111 its reverse (11112201112), we get a palindrome (32222422223).

The spelling of 21110221111 in words is "twenty-one billion, one hundred ten million, two hundred twenty-one thousand, one hundred eleven".