28397775 has 24 divisors (see below), whose sum is σ = 53659264. Its totient is φ = 12981600.

The previous prime is 28397717. The next prime is 28397779. The reversal of 28397775 is 57779382.

It is not a de Polignac number, because 28397775 - 2⁶ = 28397711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28397779) 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 23 ways as a sum of consecutive naturals, for example, 26521 + ... + 27570.

Almost surely, 2^28397775 is an apocalyptic number.

28397775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28397775 is a deficient number, since it is larger than the sum of its proper divisors (25261489).

28397775 is a wasteful number, since it uses less digits than its factorization.

28397775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54111 (or 54106 counting only the distinct ones).

The product of its digits is 740880, while the sum is 48.

The square root of 28397775 is about 5328.9562767957. The cubic root of 28397775 is about 305.0900925290.

The spelling of 28397775 in words is "twenty-eight million, three hundred ninety-seven thousand, seven hundred seventy-five".