21100020000000 has 288 divisors, whose sum is σ = 70196049985152. Its totient is φ = 5626656000000.

The previous prime is 21100019999959. The next prime is 21100020000001. The reversal of 21100020000000 is 2000112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100020000001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59824167 + ... + 60175833.

Almost surely, 2^{21100020000000} is an apocalyptic number.

21100020000000 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 21100020000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35098024992576).

21100020000000 is an abundant number, since it is smaller than the sum of its proper divisors (49096029985152).

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

21100020000000 is an frugal number, since it uses more digits than its factorization.

21100020000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351721 (or 351677 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

Adding to 21100020000000 its reverse (2000112), we get a palindrome (21100022000112).

The spelling of 21100020000000 in words is "twenty-one trillion, one hundred billion, twenty million", and thus it is an aban number.