28238787 has 24 divisors (see below), whose sum is σ = 42864640. Its totient is φ = 18574920.

The previous prime is 28238773. The next prime is 28238797. The reversal of 28238787 is 78783282.

It is not a de Polignac number, because 28238787 - 2⁶ = 28238723 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 (28238767) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18462 + ... + 19932.

Almost surely, 2^28238787 is an apocalyptic number.

28238787 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28238787 is a deficient number, since it is larger than the sum of its proper divisors (14625853).

28238787 is an equidigital number, since it uses as much as digits as its factorization.

28238787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1565 (or 1553 counting only the distinct ones).

The product of its digits is 301056, while the sum is 45.

The square root of 28238787 is about 5314.0179713659. The cubic root of 28238787 is about 304.5196667634.

The spelling of 28238787 in words is "twenty-eight million, two hundred thirty-eight thousand, seven hundred eighty-seven".