21505322300 has 144 divisors (see below), whose sum is σ = 58374097152. Its totient is φ = 6680793600.

The previous prime is 21505322221. The next prime is 21505322317. The reversal of 21505322300 is 322350512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2405639 + ... + 2414561.

Almost surely, 2^21505322300 is an apocalyptic number.

21505322300 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 21505322300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29187048576).

21505322300 is an abundant number, since it is smaller than the sum of its proper divisors (36868774852).

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

21505322300 is a wasteful number, since it uses less digits than its factorization.

21505322300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9268 (or 9261 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 23.

Adding to 21505322300 its reverse (322350512), we get a palindrome (21827672812).

The spelling of 21505322300 in words is "twenty-one billion, five hundred five million, three hundred twenty-two thousand, three hundred".