21110211220 has 48 divisors (see below), whose sum is σ = 50698545408. Its totient is φ = 7232924160.

The previous prime is 21110211217. The next prime is 21110211229. The reversal of 21110211220 is 2211201112.

It is a self number, because there is not a number n which added to its sum of digits gives 21110211220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110211229) by changing a digit.

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, 161644 + ... + 261436.

It is an arithmetic number, because the mean of its divisors is an integer number (1056219696).

Almost surely, 2^21110211220 is an apocalyptic number.

21110211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110211220 is an abundant number, since it is smaller than the sum of its proper divisors (29588334188).

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

21110211220 is a wasteful number, since it uses less digits than its factorization.

21110211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101320 (or 101318 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21110211220 its reverse (2211201112), we get a palindrome (23321412332).

The spelling of 21110211220 in words is "twenty-one billion, one hundred ten million, two hundred eleven thousand, two hundred twenty".