28721168784 has 320 divisors, whose sum is σ = 104239042560. Its totient is φ = 7354368000.

The previous prime is 28721168783. The next prime is 28721168843. The reversal of 28721168784 is 48786112782.

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

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 28721168784.

It is not an unprimeable number, because it can be changed into a prime (28721168783) by changing a digit.

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, 2355664 + ... + 2367824.

It is an arithmetic number, because the mean of its divisors is an integer number (325747008).

Almost surely, 2^28721168784 is an apocalyptic number.

28721168784 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 28721168784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52119521280).

28721168784 is an abundant number, since it is smaller than the sum of its proper divisors (75517873776).

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

28721168784 is a wasteful number, since it uses less digits than its factorization.

28721168784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12267 (or 12255 counting only the distinct ones).

The product of its digits is 2408448, while the sum is 54.

The spelling of 28721168784 in words is "twenty-eight billion, seven hundred twenty-one million, one hundred sixty-eight thousand, seven hundred eighty-four".