28505775 has 24 divisors (see below), whose sum is σ = 48231040. Its totient is φ = 14847840.

The previous prime is 28505773. The next prime is 28505801. The reversal of 28505775 is 57750582.

It is not a de Polignac number, because 28505775 - 2¹ = 28505773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28505773) 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 23 ways as a sum of consecutive naturals, for example, 1195 + ... + 7644.

Almost surely, 2^28505775 is an apocalyptic number.

28505775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28505775 is a deficient number, since it is larger than the sum of its proper divisors (19725265).

28505775 is a wasteful number, since it uses less digits than its factorization.

28505775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8895 (or 8890 counting only the distinct ones).

The product of its (nonzero) digits is 98000, while the sum is 39.

The square root of 28505775 is about 5339.0799769249. The cubic root of 28505775 is about 305.4763674805.

It can be divided in two parts, 2850577 and 5, that added together give a palindrome (2850582).

The spelling of 28505775 in words is "twenty-eight million, five hundred five thousand, seven hundred seventy-five".