21120111021020 has 192 divisors, whose sum is σ = 52784580441600. Its totient is φ = 7011930240000.

The previous prime is 21120111020971. The next prime is 21120111021043. The reversal of 21120111021020 is 2012011102112.

It is a junction number, because it is equal to n+sod(n) for n = 21120111020986 and 21120111021004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 65418995 + ... + 65741045.

It is an arithmetic number, because the mean of its divisors is an integer number (274919689800).

Almost surely, 2^{21120111021020} is an apocalyptic number.

21120111021020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21120111021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26392290220800).

21120111021020 is an abundant number, since it is smaller than the sum of its proper divisors (31664469420580).

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

21120111021020 is a wasteful number, since it uses less digits than its factorization.

21120111021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322660 (or 322658 counting only the distinct ones).

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

Adding to 21120111021020 its reverse (2012011102112), we get a palindrome (23132122123132).

The spelling of 21120111021020 in words is "twenty-one trillion, one hundred twenty billion, one hundred eleven million, twenty-one thousand, twenty".