28535721984 has 520 divisors, whose sum is σ = 106373961408. Its totient is φ = 7405240320.

The previous prime is 28535721971. The next prime is 28535721989. The reversal of 28535721984 is 48912753582.

28535721984 is a `hidden beast` number, since 2 + 8 + 53 + 572 + 19 + 8 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 28535721984.

It is not an unprimeable number, because it can be changed into a prime (28535721989) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 25546194 + ... + 25547310.

Almost surely, 2^28535721984 is an apocalyptic number.

28535721984 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 28535721984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53186980704).

28535721984 is an abundant number, since it is smaller than the sum of its proper divisors (77838239424).

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

28535721984 is a wasteful number, since it uses less digits than its factorization.

28535721984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171 (or 1140 counting only the distinct ones).

The product of its digits is 4838400, while the sum is 54.

The spelling of 28535721984 in words is "twenty-eight billion, five hundred thirty-five million, seven hundred twenty-one thousand, nine hundred eighty-four".