21056122200 has 96 divisors (see below), whose sum is σ = 66662876160. Its totient is φ = 5495491200.

The previous prime is 21056122189. The next prime is 21056122201. The reversal of 21056122200 is 222165012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056122201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 345136 + ... + 401535.

It is an arithmetic number, because the mean of its divisors is an integer number (694404960).

Almost surely, 2^21056122200 is an apocalyptic number.

21056122200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21056122200 is an abundant number, since it is smaller than the sum of its proper divisors (45606753960).

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

21056122200 is a wasteful number, since it uses less digits than its factorization.

21056122200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746737 (or 746728 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21056122200 its reverse (222165012), we get a palindrome (21278287212).

The spelling of 21056122200 in words is "twenty-one billion, fifty-six million, one hundred twenty-two thousand, two hundred".