21540424200 has 96 divisors (see below), whose sum is σ = 68404059360. Its totient is φ = 5604006400.

The previous prime is 21540424181. The next prime is 21540424201. The reversal of 21540424200 is 242404512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21540424201) by changing a digit.

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, 413214 + ... + 462413.

It is an arithmetic number, because the mean of its divisors is an integer number (712542285).

Almost surely, 2^21540424200 is an apocalyptic number.

21540424200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21540424200 is an abundant number, since it is smaller than the sum of its proper divisors (46863635160).

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

21540424200 is a wasteful number, since it uses less digits than its factorization.

21540424200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875687 (or 875678 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 24.

Adding to 21540424200 its reverse (242404512), we get a palindrome (21782828712).

The spelling of 21540424200 in words is "twenty-one billion, five hundred forty million, four hundred twenty-four thousand, two hundred".