21111033220 has 24 divisors (see below), whose sum is σ = 44376634008. Its totient is φ = 8436134400.

The previous prime is 21111033191. The next prime is 21111033233. The reversal of 21111033220 is 2233011112.

It can be written as a sum of positive squares in 4 ways, for example, as 4604436736 + 16506596484 = 67856^2 + 128478^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21111033194 and 21111033203.

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, 496501 + ... + 537340.

It is an arithmetic number, because the mean of its divisors is an integer number (1849026417).

Almost surely, 2^21111033220 is an apocalyptic number.

21111033220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111033220 is an abundant number, since it is smaller than the sum of its proper divisors (23265600788).

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

21111033220 is a wasteful number, since it uses less digits than its factorization.

21111033220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034871 (or 1034869 counting only the distinct ones).

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

Adding to 21111033220 its reverse (2233011112), we get a palindrome (23344044332).

The spelling of 21111033220 in words is "twenty-one billion, one hundred eleven million, thirty-three thousand, two hundred twenty".