21000022200 has 96 divisors (see below), whose sum is σ = 72333428400. Its totient is φ = 5600004480.

The previous prime is 21000022163. The next prime is 21000022207. The reversal of 21000022200 is 222000012.

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

21000022200 is a modest number, since divided by 22200 gives 21000 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000022207) 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, 1939047 + ... + 1949846.

Almost surely, 2^21000022200 is an apocalyptic number.

21000022200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000022200 is an abundant number, since it is smaller than the sum of its proper divisors (51333406200).

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

21000022200 is a wasteful number, since it uses less digits than its factorization.

21000022200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3888918 (or 3888903 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

Adding to 21000022200 its reverse (222000012), we get a palindrome (21222022212).

The spelling of 21000022200 in words is "twenty-one billion, twenty-two thousand, two hundred".