28644375 has 20 divisors (see below), whose sum is σ = 47728472. Its totient is φ = 15276000.

The previous prime is 28644359. The next prime is 28644377. The reversal of 28644375 is 57344682.

It is a happy number.

It is not a de Polignac number, because 28644375 - 2⁴ = 28644359 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 (28644377) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5764 + ... + 9513.

Almost surely, 2^28644375 is an apocalyptic number.

28644375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28644375 is a deficient number, since it is larger than the sum of its proper divisors (19084097).

28644375 is an equidigital number, since it uses as much as digits as its factorization.

28644375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15300 (or 15285 counting only the distinct ones).

The product of its digits is 161280, while the sum is 39.

The square root of 28644375 is about 5352.0440020613. The cubic root of 28644375 is about 305.9706601798.

It can be divided in two parts, 286443 and 75, that multiplied together give a square (21483225 = 4635²).

The spelling of 28644375 in words is "twenty-eight million, six hundred forty-four thousand, three hundred seventy-five".