21243224000 has 56 divisors (see below), whose sum is σ = 52608864048. Its totient is φ = 8497286400.

The previous prime is 21243223957. The next prime is 21243224033. The reversal of 21243224000 is 42234212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1319702 + ... + 1335701.

Almost surely, 2^21243224000 is an apocalyptic number.

21243224000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243224000 is an abundant number, since it is smaller than the sum of its proper divisors (31365640048).

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

21243224000 is an equidigital number, since it uses as much as digits as its factorization.

21243224000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2655430 (or 2655410 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21243224000 its reverse (42234212), we get a palindrome (21285458212).

The spelling of 21243224000 in words is "twenty-one billion, two hundred forty-three million, two hundred twenty-four thousand".