28721567807424 has 336 divisors, whose sum is σ = 89225893785600. Its totient is φ = 8798820507648.

The previous prime is 28721567807341. The next prime is 28721567807521. The reversal of 28721567807424 is 42470876512782.

28721567807424 is a `hidden beast` number, since 2 + 8 + 7 + 21 + 567 + 8 + 0 + 7 + 42 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 201967257 + ... + 202109415.

Almost surely, 2^{28721567807424} is an apocalyptic number.

28721567807424 is a gapful number since it is divisible by the number (24) 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 28721567807424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44612946892800).

28721567807424 is an abundant number, since it is smaller than the sum of its proper divisors (60504325978176).

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

28721567807424 is a wasteful number, since it uses less digits than its factorization.

28721567807424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142680 (or 142667 counting only the distinct ones).

The product of its (nonzero) digits is 84295680, while the sum is 63.

The spelling of 28721567807424 in words is "twenty-eight trillion, seven hundred twenty-one billion, five hundred sixty-seven million, eight hundred seven thousand, four hundred twenty-four".