28521199720800 has 720 divisors, whose sum is σ = 104982239300400. Its totient is φ = 7534890086400.

The previous prime is 28521199720771. The next prime is 28521199720843. The reversal of 28521199720800 is 802799112582.

28521199720800 is a `hidden beast` number, since 2 + 8 + 521 + 1 + 9 + 97 + 20 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 4584661690 + ... + 4584667910.

It is an arithmetic number, because the mean of its divisors is an integer number (145808665695).

Almost surely, 2^{28521199720800} is an apocalyptic number.

28521199720800 is a gapful number since it is divisible by the number (20) 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 28521199720800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52491119650200).

28521199720800 is an abundant number, since it is smaller than the sum of its proper divisors (76461039579600).

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

28521199720800 is a wasteful number, since it uses less digits than its factorization.

28521199720800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6901 (or 6879 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 28521199720800 in words is "twenty-eight trillion, five hundred twenty-one billion, one hundred ninety-nine million, seven hundred twenty thousand, eight hundred".