28305615 has 32 divisors (see below), whose sum is σ = 49029120. Its totient is φ = 13862016.

The previous prime is 28305593. The next prime is 28305619. The reversal of 28305615 is 51650382.

It is not a de Polignac number, because 28305615 - 2⁵ = 28305583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28305619) 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 31 ways as a sum of consecutive naturals, for example, 73714 + ... + 74096.

It is an arithmetic number, because the mean of its divisors is an integer number (1532160).

Almost surely, 2^28305615 is an apocalyptic number.

28305615 is a deficient number, since it is larger than the sum of its proper divisors (20723505).

28305615 is a wasteful number, since it uses less digits than its factorization.

28305615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 28305615 is about 5320.3021530736. The cubic root of 28305615 is about 304.7596960541.

Adding to 28305615 its reverse (51650382), we get a palindrome (79955997).

It can be divided in two parts, 28305 and 615, that added together give a triangular number (28920 = T₂₄₀).

The spelling of 28305615 in words is "twenty-eight million, three hundred five thousand, six hundred fifteen".