28123788 has 72 divisors (see below), whose sum is σ = 82464256. Its totient is φ = 7302240.

The previous prime is 28123787. The next prime is 28123793. The reversal of 28123788 is 88732182.

It is a super-3 number, since 3×28123788³ (a number of 23 digits) contains 333 as substring.

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 23 ways as a sum of consecutive naturals, for example, 8781 + ... + 11547.

Almost surely, 2^28123788 is an apocalyptic number.

28123788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28123788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41232128).

28123788 is an abundant number, since it is smaller than the sum of its proper divisors (54340468).

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

28123788 is a wasteful number, since it uses less digits than its factorization.

28123788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2803 (or 2790 counting only the distinct ones).

The product of its digits is 43008, while the sum is 39.

The square root of 28123788 is about 5303.1865892122. The cubic root of 28123788 is about 304.1057313433.

The spelling of 28123788 in words is "twenty-eight million, one hundred twenty-three thousand, seven hundred eighty-eight".