21110221220 has 24 divisors (see below), whose sum is σ = 48361598208. Its totient is φ = 7676444000.

The previous prime is 21110221201. The next prime is 21110221303. The reversal of 21110221220 is 2212201112.

It is a junction number, because it is equal to n+sod(n) for n = 21110221195 and 21110221204.

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, 47977556 + ... + 47977995.

It is an arithmetic number, because the mean of its divisors is an integer number (2015066592).

Almost surely, 2^21110221220 is an apocalyptic number.

21110221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110221220 is an abundant number, since it is smaller than the sum of its proper divisors (27251376988).

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

21110221220 is a wasteful number, since it uses less digits than its factorization.

21110221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95955571 (or 95955569 counting only the distinct ones).

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

Adding to 21110221220 its reverse (2212201112), we get a palindrome (23322422332).

The spelling of 21110221220 in words is "twenty-one billion, one hundred ten million, two hundred twenty-one thousand, two hundred twenty".