21200011100 has 72 divisors (see below), whose sum is σ = 46629963408. Its totient is φ = 8365248000.

The previous prime is 21200011069. The next prime is 21200011117. The reversal of 21200011100 is 111000212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2854592 + ... + 2862008.

Almost surely, 2^21200011100 is an apocalyptic number.

21200011100 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 21200011100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23314981704).

21200011100 is an abundant number, since it is smaller than the sum of its proper divisors (25429952308).

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

21200011100 is a wasteful number, since it uses less digits than its factorization.

21200011100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7815 (or 7808 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21200011100 its reverse (111000212), we get a palindrome (21311011312).

The spelling of 21200011100 in words is "twenty-one billion, two hundred million, eleven thousand, one hundred".