21111110221 has 8 divisors (see below), whose sum is σ = 22399614720. Its totient is φ = 19827791808.

The previous prime is 21111110161. The next prime is 21111110231. The reversal of 21111110221 is 12201111112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21111110221 - 2⁷ = 21111110093 is a prime.

It is a super-3 number, since 3×21111110221³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111110231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1288131 + ... + 1304416.

It is an arithmetic number, because the mean of its divisors is an integer number (2799951840).

Almost surely, 2^21111110221 is an apocalyptic number.

It is an amenable number.

21111110221 is a deficient number, since it is larger than the sum of its proper divisors (1288504499).

21111110221 is a wasteful number, since it uses less digits than its factorization.

21111110221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2593043.

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

Adding to 21111110221 its reverse (12201111112), we get a palindrome (33312221333).

The spelling of 21111110221 in words is "twenty-one billion, one hundred eleven million, one hundred ten thousand, two hundred twenty-one".