21002100020000 has 240 divisors, whose sum is σ = 56457154952352. Its totient is φ = 7624700160000.

The previous prime is 21002100019981. The next prime is 21002100020039. The reversal of 21002100020000 is 2000120012.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21002100020000.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 135662639 + ... + 135817361.

Almost surely, 2^{21002100020000} is an apocalyptic number.

21002100020000 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 21002100020000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28228577476176).

21002100020000 is an abundant number, since it is smaller than the sum of its proper divisors (35455054932352).

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

21002100020000 is a wasteful number, since it uses less digits than its factorization.

21002100020000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155381 (or 155358 counting only the distinct ones).

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

Adding to 21002100020000 its reverse (2000120012), we get a palindrome (21004100140012).

The spelling of 21002100020000 in words is "twenty-one trillion, two billion, one hundred million, twenty thousand".