21221122200 has 96 divisors (see below), whose sum is σ = 66618355200. Its totient is φ = 5587320960.

The previous prime is 21221122187. The next prime is 21221122213. The reversal of 21221122200 is 222112212.

It is an interprime number because it is at equal distance from previous prime (21221122187) and next prime (21221122213).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21221122200.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 176452 + ... + 271251.

It is an arithmetic number, because the mean of its divisors is an integer number (693941200).

Almost surely, 2^21221122200 is an apocalyptic number.

21221122200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221122200 is an abundant number, since it is smaller than the sum of its proper divisors (45397233000).

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

21221122200 is a wasteful number, since it uses less digits than its factorization.

21221122200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447801 (or 447792 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21221122200 its reverse (222112212), we get a palindrome (21443234412).

The spelling of 21221122200 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred".