28388775 has 24 divisors (see below), whose sum is σ = 47474640. Its totient is φ = 14967040.

The previous prime is 28388741. The next prime is 28388791. The reversal of 28388775 is 57788382.

It is not a de Polignac number, because 28388775 - 2¹¹ = 28386727 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4549 + ... + 8801.

It is an arithmetic number, because the mean of its divisors is an integer number (1978110).

Almost surely, 2^28388775 is an apocalyptic number.

28388775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28388775 is a deficient number, since it is larger than the sum of its proper divisors (19085865).

28388775 is a wasteful number, since it uses less digits than its factorization.

28388775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4355 (or 4350 counting only the distinct ones).

The product of its digits is 752640, while the sum is 48.

The square root of 28388775 is about 5328.1117668457. Note that the first 3 decimals coincide. The cubic root of 28388775 is about 305.0578587717.

The spelling of 28388775 in words is "twenty-eight million, three hundred eighty-eight thousand, seven hundred seventy-five".