28123782 has 16 divisors (see below), whose sum is σ = 56309040. Its totient is φ = 9364352.

The previous prime is 28123759. The next prime is 28123787. The reversal of 28123782 is 28732182.

It is a super-2 number, since 2×28123782² = 1581894227967048, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28123787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5194 + ... + 9122.

It is an arithmetic number, because the mean of its divisors is an integer number (3519315).

Almost surely, 2^28123782 is an apocalyptic number.

28123782 is an abundant number, since it is smaller than the sum of its proper divisors (28185258).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28123782 is a wasteful number, since it uses less digits than its factorization.

28123782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5127.

The product of its digits is 10752, while the sum is 33.

The square root of 28123782 is about 5303.1860235145. The cubic root of 28123782 is about 304.1057097171.

Subtracting 28123782 from its reverse (28732182), we obtain a square (608400 = 780²).

The spelling of 28123782 in words is "twenty-eight million, one hundred twenty-three thousand, seven hundred eighty-two".