21111112220 has 48 divisors (see below), whose sum is σ = 49923772416. Its totient is φ = 7429128000.

The previous prime is 21111112207. The next prime is 21111112229. The reversal of 21111112220 is 2221111112.

It is a junction number, because it is equal to n+sod(n) for n = 21111112195 and 21111112204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111112229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1540916 + ... + 1554555.

It is an arithmetic number, because the mean of its divisors is an integer number (1040078592).

Almost surely, 2^21111112220 is an apocalyptic number.

21111112220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111112220 is an abundant number, since it is smaller than the sum of its proper divisors (28812660196).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111112220 is a wasteful number, since it uses less digits than its factorization.

21111112220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3095522 (or 3095520 counting only the distinct ones).

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

Adding to 21111112220 its reverse (2221111112), we get a palindrome (23332223332).

It can be divided in two parts, 21111 and 112220, that added together give a palindrome (133331).

The spelling of 21111112220 in words is "twenty-one billion, one hundred eleven million, one hundred twelve thousand, two hundred twenty".