21001020112000 has 256 divisors, whose sum is σ = 55475628624000. Its totient is φ = 7883892633600.

The previous prime is 21001020111997. The next prime is 21001020112001. The reversal of 21001020112000 is 21102010012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21001020112001) 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, 32205186 + ... + 32850814.

Almost surely, 2^{21001020112000} is an apocalyptic number.

21001020112000 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 21001020112000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27737814312000).

21001020112000 is an abundant number, since it is smaller than the sum of its proper divisors (34474608512000).

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

21001020112000 is a wasteful number, since it uses less digits than its factorization.

21001020112000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645784 (or 645762 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21001020112000 its reverse (21102010012), we get a palindrome (21022122122012).

The spelling of 21001020112000 in words is "twenty-one trillion, one billion, twenty million, one hundred twelve thousand".