21644034200 has 24 divisors (see below), whose sum is σ = 50322379980. Its totient is φ = 8657613600.

The previous prime is 21644034179. The next prime is 21644034227. The reversal of 21644034200 is 243044612.

It is a self number, because there is not a number n which added to its sum of digits gives 21644034200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54109886 + ... + 54110285.

Almost surely, 2^21644034200 is an apocalyptic number.

21644034200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21644034200 is an abundant number, since it is smaller than the sum of its proper divisors (28678345780).

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

21644034200 is a wasteful number, since it uses less digits than its factorization.

21644034200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108220187 (or 108220178 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21644034200 its reverse (243044612), we get a palindrome (21887078812).

The spelling of 21644034200 in words is "twenty-one billion, six hundred forty-four million, thirty-four thousand, two hundred".