28573937581 has 4 divisors (see below), whose sum is σ = 32655928672. Its totient is φ = 24491946492.

The previous prime is 28573937563. The next prime is 28573937617. The reversal of 28573937581 is 18573937582.

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 28573937581 - 2⁵ = 28573937549 is a prime.

It is a super-2 number, since 2×28573937581² (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 (28573937881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2040995535 + ... + 2040995548.

It is an arithmetic number, because the mean of its divisors is an integer number (8163982168).

Almost surely, 2^28573937581 is an apocalyptic number.

It is an amenable number.

28573937581 is a deficient number, since it is larger than the sum of its proper divisors (4081991091).

28573937581 is an equidigital number, since it uses as much as digits as its factorization.

28573937581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4081991090.

The product of its digits is 12700800, while the sum is 58.

Subtracting from 28573937581 its reverse (18573937582), we obtain a palindrome (9999999999).

The spelling of 28573937581 in words is "twenty-eight billion, five hundred seventy-three million, nine hundred thirty-seven thousand, five hundred eighty-one".