21011113220 has 48 divisors (see below), whose sum is σ = 45227464128. Its totient is φ = 8194811520.

The previous prime is 21011113199. The next prime is 21011113241. The reversal of 21011113220 is 2231111012.

It is an interprime number because it is at equal distance from previous prime (21011113199) and next prime (21011113241).

It is a junction number, because it is equal to n+sod(n) for n = 21011113195 and 21011113204.

It is an unprimeable number.

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, 484010 + ... + 525630.

It is an arithmetic number, because the mean of its divisors is an integer number (942238836).

Almost surely, 2^21011113220 is an apocalyptic number.

21011113220 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 21011113220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22613732064).

21011113220 is an abundant number, since it is smaller than the sum of its proper divisors (24216350908).

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

21011113220 is a wasteful number, since it uses less digits than its factorization.

21011113220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42260 (or 42258 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21011113220 its reverse (2231111012), we get a palindrome (23242224232).

The spelling of 21011113220 in words is "twenty-one billion, eleven million, one hundred thirteen thousand, two hundred twenty".