28531013 has 12 divisors (see below), whose sum is σ = 33256608. Its totient is φ = 23977200.

The previous prime is 28530979. The next prime is 28531051. The reversal of 28531013 is 31013582.

It is not a de Polignac number, because 28531013 - 2¹⁰ = 28529989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28531013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28531073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18938 + ... + 20388.

It is an arithmetic number, because the mean of its divisors is an integer number (2771384).

Almost surely, 2^28531013 is an apocalyptic number.

It is an amenable number.

28531013 is a deficient number, since it is larger than the sum of its proper divisors (4725595).

28531013 is an equidigital number, since it uses as much as digits as its factorization.

28531013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1564 (or 1511 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 28531013 is about 5341.4429698350. The cubic root of 28531013 is about 305.5664935270.

Adding to 28531013 its reverse (31013582), we get a palindrome (59544595).

The spelling of 28531013 in words is "twenty-eight million, five hundred thirty-one thousand, thirteen".