28320381665280 has 1152 divisors, whose sum is σ = 110093013596160. Its totient is φ = 6876309749760.

The previous prime is 28320381665273. The next prime is 28320381665299. The reversal of 28320381665280 is 8256618302382.

It is a happy number.

28320381665280 is a `hidden beast` number, since 2 + 8 + 3 + 20 + 38 + 1 + 66 + 528 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9325115922 + ... + 9325118958.

It is an arithmetic number, because the mean of its divisors is an integer number (95566852080).

Almost surely, 2^{28320381665280} is an apocalyptic number.

28320381665280 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 28320381665280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55046506798080).

28320381665280 is an abundant number, since it is smaller than the sum of its proper divisors (81772631930880).

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

28320381665280 is an equidigital number, since it uses as much as digits as its factorization.

28320381665280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3133 (or 3095 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 54.

The spelling of 28320381665280 in words is "twenty-eight trillion, three hundred twenty billion, three hundred eighty-one million, six hundred sixty-five thousand, two hundred eighty".