21020000021100 has 216 divisors, whose sum is σ = 68609775842608. Its totient is φ = 5582073139200.

The previous prime is 21020000021051. The next prime is 21020000021117. The reversal of 21020000021100 is 112000002012.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4061652 + ... + 7650948.

Almost surely, 2^{21020000021100} is an apocalyptic number.

21020000021100 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 21020000021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34304887921304).

21020000021100 is an abundant number, since it is smaller than the sum of its proper divisors (47589775821508).

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

21020000021100 is a wasteful number, since it uses less digits than its factorization.

21020000021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3589567 (or 3589548 counting only the distinct ones).

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

Adding to 21020000021100 its reverse (112000002012), we get a palindrome (21132000023112).

The spelling of 21020000021100 in words is "twenty-one trillion, twenty billion, twenty-one thousand, one hundred".