21784745500 has 48 divisors (see below), whose sum is σ = 54374733504. Its totient is φ = 7469054400.

The previous prime is 21784745453. The next prime is 21784745513. The reversal of 21784745500 is 554748712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3108607 + ... + 3115606.

It is an arithmetic number, because the mean of its divisors is an integer number (1132806948).

Almost surely, 2^21784745500 is an apocalyptic number.

21784745500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21784745500 is an abundant number, since it is smaller than the sum of its proper divisors (32589988004).

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

21784745500 is a wasteful number, since it uses less digits than its factorization.

21784745500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6224239 (or 6224227 counting only the distinct ones).

The product of its (nonzero) digits is 313600, while the sum is 43.

The spelling of 21784745500 in words is "twenty-one billion, seven hundred eighty-four million, seven hundred forty-five thousand, five hundred".