28507306 has 4 divisors (see below), whose sum is σ = 42760962. Its totient is φ = 14253652.

The previous prime is 28507291. The next prime is 28507307. The reversal of 28507306 is 60370582.

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

It can be written as a sum of positive squares in only one way, i.e., 27931225 + 576081 = 5285^2 + 759^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (28507307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7126825 + ... + 7126828.

Almost surely, 2^28507306 is an apocalyptic number.

28507306 is a deficient number, since it is larger than the sum of its proper divisors (14253656).

28507306 is a wasteful number, since it uses less digits than its factorization.

28507306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14253655.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 28507306 is about 5339.2233517619. The cubic root of 28507306 is about 305.4818362665.

Adding to 28507306 its reverse (60370582), we get a palindrome (88877888).

The spelling of 28507306 in words is "twenty-eight million, five hundred seven thousand, three hundred six".