28281975 has 48 divisors (see below), whose sum is σ = 49996800. Its totient is φ = 14065920.

The previous prime is 28281971. The next prime is 28281991. The reversal of 28281975 is 57918282.

It is not a de Polignac number, because 28281975 - 2² = 28281971 is a prime.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28281971) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 126714 + ... + 126936.

It is an arithmetic number, because the mean of its divisors is an integer number (1041600).

Almost surely, 2^28281975 is an apocalyptic number.

28281975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28281975 is a deficient number, since it is larger than the sum of its proper divisors (21714825).

28281975 is a wasteful number, since it uses less digits than its factorization.

28281975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 339 counting only the distinct ones).

The product of its digits is 80640, while the sum is 42.

The square root of 28281975 is about 5318.0800106805. The cubic root of 28281975 is about 304.6748303739.

The spelling of 28281975 in words is "twenty-eight million, two hundred eighty-one thousand, nine hundred seventy-five".