21201112220 has 24 divisors (see below), whose sum is σ = 44707085808. Its totient is φ = 8445254400.

The previous prime is 21201112217. The next prime is 21201112241. The reversal of 21201112220 is 2221110212.

It is a junction number, because it is equal to n+sod(n) for n = 21201112195 and 21201112204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2194466 + ... + 2204105.

It is an arithmetic number, because the mean of its divisors is an integer number (1862795242).

Almost surely, 2^21201112220 is an apocalyptic number.

21201112220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201112220 is an abundant number, since it is smaller than the sum of its proper divisors (23505973588).

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

21201112220 is a wasteful number, since it uses less digits than its factorization.

21201112220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4398821 (or 4398819 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21201112220 its reverse (2221110212), we get a palindrome (23422222432).

The spelling of 21201112220 in words is "twenty-one billion, two hundred one million, one hundred twelve thousand, two hundred twenty".