28748240 has 20 divisors (see below), whose sum is σ = 66839844. Its totient is φ = 11499264.

The previous prime is 28748231. The next prime is 28748243. The reversal of 28748240 is 4284782.

It can be written as a sum of positive squares in 2 ways, for example, as 11641744 + 17106496 = 3412^2 + 4136^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×28748240² = 1652922606195200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 28748240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28748243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179597 + ... + 179756.

Almost surely, 2^28748240 is an apocalyptic number.

28748240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28748240 is an abundant number, since it is smaller than the sum of its proper divisors (38091604).

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

28748240 is a wasteful number, since it uses less digits than its factorization.

28748240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359366 (or 359360 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 35.

The square root of 28748240 is about 5361.7385240237. The cubic root of 28748240 is about 306.3400323937.

The spelling of 28748240 in words is "twenty-eight million, seven hundred forty-eight thousand, two hundred forty".