21221100111020 has 48 divisors (see below), whose sum is σ = 44582405355936. Its totient is φ = 8484993984000.

The previous prime is 21221100111019. The next prime is 21221100111077. The reversal of 21221100111020 is 2011100112212.

It is a junction number, because it is equal to n+sod(n) for n = 21221100110986 and 21221100111004.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 969830480 + ... + 969852360.

It is an arithmetic number, because the mean of its divisors is an integer number (928800111582).

Almost surely, 2^{21221100111020} is an apocalyptic number.

21221100111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221100111020 is an abundant number, since it is smaller than the sum of its proper divisors (23361305244916).

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

21221100111020 is a wasteful number, since it uses less digits than its factorization.

21221100111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39362 (or 39360 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21221100111020 its reverse (2011100112212), we get a palindrome (23232200223232).

The spelling of 21221100111020 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred million, one hundred eleven thousand, twenty".