21543264000 has 864 divisors, whose sum is σ = 84894351360. Its totient is φ = 5225472000.

The previous prime is 21543263999. The next prime is 21543264011. The reversal of 21543264000 is 46234512.

21543264000 is a `hidden beast` number, since 2 + 15 + 4 + 3 + 2 + 640 + 0 + 0 = 666.

It is a super-2 number, since 2×21543264000² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 169631937 + ... + 169632063.

Almost surely, 2^21543264000 is an apocalyptic number.

21543264000 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 21543264000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42447175680).

21543264000 is an abundant number, since it is smaller than the sum of its proper divisors (63351087360).

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

21543264000 is a wasteful number, since it uses less digits than its factorization.

21543264000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21543264000 its reverse (46234512), we get a palindrome (21589498512).

The spelling of 21543264000 in words is "twenty-one billion, five hundred forty-three million, two hundred sixty-four thousand".