28042513 has 4 divisors (see below), whose sum is σ = 28118068. Its totient is φ = 27966960.

The previous prime is 28042501. The next prime is 28042517. The reversal of 28042513 is 31524082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16257024 + 11785489 = 4032^2 + 3433^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28042513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28042517) 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 3 ways as a sum of consecutive naturals, for example, 37218 + ... + 37963.

It is an arithmetic number, because the mean of its divisors is an integer number (7029517).

Almost surely, 2^28042513 is an apocalyptic number.

It is an amenable number.

28042513 is a deficient number, since it is larger than the sum of its proper divisors (75555).

28042513 is an equidigital number, since it uses as much as digits as its factorization.

28042513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75554.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 28042513 is about 5295.5181993833. The cubic root of 28042513 is about 303.8125034094.

Adding to 28042513 its reverse (31524082), we get a palindrome (59566595).

The spelling of 28042513 in words is "twenty-eight million, forty-two thousand, five hundred thirteen".