28324388581 has 4 divisors (see below), whose sum is σ = 28346127712. Its totient is φ = 28302649452.

The previous prime is 28324388513. The next prime is 28324388633. The reversal of 28324388581 is 18588342382.

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 28324388581 - 2⁹ = 28324388069 is a prime.

It is a super-2 number, since 2×28324388581² (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 (28324388501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10867611 + ... + 10870216.

It is an arithmetic number, because the mean of its divisors is an integer number (7086531928).

Almost surely, 2^28324388581 is an apocalyptic number.

It is an amenable number.

28324388581 is a deficient number, since it is larger than the sum of its proper divisors (21739131).

28324388581 is a wasteful number, since it uses less digits than its factorization.

28324388581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21739130.

The product of its digits is 2949120, while the sum is 52.

The spelling of 28324388581 in words is "twenty-eight billion, three hundred twenty-four million, three hundred eighty-eight thousand, five hundred eighty-one".