21508400200 has 48 divisors (see below), whose sum is σ = 57150895680. Its totient is φ = 7374308160.

The previous prime is 21508400189. The next prime is 21508400203. The reversal of 21508400200 is 200480512.

It is a super-2 number, since 2×21508400200² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21508400203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7680172 + ... + 7682971.

It is an arithmetic number, because the mean of its divisors is an integer number (1190643660).

Almost surely, 2^21508400200 is an apocalyptic number.

21508400200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21508400200 is an abundant number, since it is smaller than the sum of its proper divisors (35642495480).

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

21508400200 is a wasteful number, since it uses less digits than its factorization.

21508400200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15363166 (or 15363157 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 21508400200 its reverse (200480512), we get a palindrome (21708880712).

The spelling of 21508400200 in words is "twenty-one billion, five hundred eight million, four hundred thousand, two hundred".