21112202221 has 16 divisors (see below), whose sum is σ = 23574228480. Its totient is φ = 18740902320.

The previous prime is 21112202213. The next prime is 21112202227. The reversal of 21112202221 is 12220221112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21112202221 - 2³ = 21112202213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112202195 and 21112202204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112202227) 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 15 ways as a sum of consecutive naturals, for example, 2759920 + ... + 2767558.

It is an arithmetic number, because the mean of its divisors is an integer number (1473389280).

Almost surely, 2^21112202221 is an apocalyptic number.

It is an amenable number.

21112202221 is a deficient number, since it is larger than the sum of its proper divisors (2462026259).

21112202221 is a wasteful number, since it uses less digits than its factorization.

21112202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13536.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21112202221 its reverse (12220221112), we get a palindrome (33332423333).

The spelling of 21112202221 in words is "twenty-one billion, one hundred twelve million, two hundred two thousand, two hundred twenty-one".