21111303220 has 96 divisors (see below), whose sum is σ = 52018864128. Its totient is φ = 7046186112.

The previous prime is 21111303209. The next prime is 21111303247. The reversal of 21111303220 is 2230311112.

It is a junction number, because it is equal to n+sod(n) for n = 21111303194 and 21111303203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1842429 + ... + 1853851.

It is an arithmetic number, because the mean of its divisors is an integer number (541863168).

Almost surely, 2^21111303220 is an apocalyptic number.

21111303220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111303220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26009432064).

21111303220 is an abundant number, since it is smaller than the sum of its proper divisors (30907560908).

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

21111303220 is a wasteful number, since it uses less digits than its factorization.

21111303220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11789 (or 11787 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21111303220 its reverse (2230311112), we get a palindrome (23341614332).

The spelling of 21111303220 in words is "twenty-one billion, one hundred eleven million, three hundred three thousand, two hundred twenty".