21220111111020 has 96 divisors (see below), whose sum is σ = 62950492785600. Its totient is φ = 5322521370624.

The previous prime is 21220111111019. The next prime is 21220111111021. The reversal of 21220111111020 is 2011111102212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21220111111019) and next prime (21220111111021).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21220111111021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4823715 + ... + 8106074.

It is an arithmetic number, because the mean of its divisors is an integer number (655734299850).

Almost surely, 2^{21220111111020} is an apocalyptic number.

21220111111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220111111020 is an abundant number, since it is smaller than the sum of its proper divisors (41730381674580).

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

21220111111020 is a wasteful number, since it uses less digits than its factorization.

21220111111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12931427 (or 12931425 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21220111111020 its reverse (2011111102212), we get a palindrome (23231222213232).

The spelling of 21220111111020 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, one hundred eleven thousand, twenty".