21000011002020 has 192 divisors, whose sum is σ = 65763959788800. Its totient is φ = 5563110758400.

The previous prime is 21000011001973. The next prime is 21000011002037. The reversal of 21000011002020 is 2020011000012.

21000011002020 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21000011002020² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21000011001993 and 21000011002011.

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, 424638295 + ... + 424687745.

It is an arithmetic number, because the mean of its divisors is an integer number (342520623900).

Almost surely, 2^{21000011002020} is an apocalyptic number.

21000011002020 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 21000011002020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32881979894400).

21000011002020 is an abundant number, since it is smaller than the sum of its proper divisors (44763948786780).

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

21000011002020 is a wasteful number, since it uses less digits than its factorization.

21000011002020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54635 (or 54627 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21000011002020 its reverse (2020011000012), we get a palindrome (23020022002032).

The spelling of 21000011002020 in words is "twenty-one trillion, eleven million, two thousand, twenty".