28528358581 has 4 divisors (see below), whose sum is σ = 28536590592. Its totient is φ = 28520126572.

The previous prime is 28528358567. The next prime is 28528358647. The reversal of 28528358581 is 18585382582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28528358581 - 2⁹ = 28528358069 is a prime.

It is a super-2 number, since 2×28528358581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28528358081) 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 3 ways as a sum of consecutive naturals, for example, 4110805 + ... + 4117738.

It is an arithmetic number, because the mean of its divisors is an integer number (7134147648).

Almost surely, 2^28528358581 is an apocalyptic number.

It is an amenable number.

28528358581 is a deficient number, since it is larger than the sum of its proper divisors (8232011).

28528358581 is an equidigital number, since it uses as much as digits as its factorization.

28528358581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8232010.

The product of its digits is 6144000, while the sum is 55.

The spelling of 28528358581 in words is "twenty-eight billion, five hundred twenty-eight million, three hundred fifty-eight thousand, five hundred eighty-one".