28523821680 has 320 divisors, whose sum is σ = 105833226240. Its totient is φ = 7040563200.

The previous prime is 28523821643. The next prime is 28523821699. The reversal of 28523821680 is 8612832582.

28523821680 is a `hidden beast` number, since 28 + 523 + 8 + 21 + 6 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1530820 + ... + 1549340.

It is an arithmetic number, because the mean of its divisors is an integer number (330728832).

Almost surely, 2^28523821680 is an apocalyptic number.

28523821680 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 28523821680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52916613120).

28523821680 is an abundant number, since it is smaller than the sum of its proper divisors (77309404560).

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

28523821680 is a wasteful number, since it uses less digits than its factorization.

28523821680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18597 (or 18585 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 28523821680 in words is "twenty-eight billion, five hundred twenty-three million, eight hundred twenty-one thousand, six hundred eighty".