21110112221 has 4 divisors (see below), whose sum is σ = 23029213344. Its totient is φ = 19191011100.

The previous prime is 21110112197. The next prime is 21110112223. The reversal of 21110112221 is 12221101112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21110112221 - 2⁶ = 21110112157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110112196 and 21110112205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110112223) 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, 959550545 + ... + 959550566.

It is an arithmetic number, because the mean of its divisors is an integer number (5757303336).

Almost surely, 2^21110112221 is an apocalyptic number.

It is an amenable number.

21110112221 is a deficient number, since it is larger than the sum of its proper divisors (1919101123).

21110112221 is a wasteful number, since it uses less digits than its factorization.

21110112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919101122.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21110112221 its reverse (12221101112), we get a palindrome (33331213333).

It can be divided in two parts, 211101 and 12221, that added together give a palindrome (223322).

The spelling of 21110112221 in words is "twenty-one billion, one hundred ten million, one hundred twelve thousand, two hundred twenty-one".