28868240 has 20 divisors (see below), whose sum is σ = 67118844. Its totient is φ = 11547264.

The previous prime is 28868237. The next prime is 28868249. The reversal of 28868240 is 4286882.

It can be written as a sum of positive squares in 2 ways, for example, as 20757136 + 8111104 = 4556^2 + 2848^2 .

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

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28868194 and 28868203.

It is not an unprimeable number, because it can be changed into a prime (28868249) 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, 180347 + ... + 180506.

Almost surely, 2^28868240 is an apocalyptic number.

28868240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28868240 is an abundant number, since it is smaller than the sum of its proper divisors (38250604).

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

28868240 is a wasteful number, since it uses less digits than its factorization.

28868240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360866 (or 360860 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 38.

The square root of 28868240 is about 5372.9172709060. The cubic root of 28868240 is about 306.7656790139.

The spelling of 28868240 in words is "twenty-eight million, eight hundred sixty-eight thousand, two hundred forty".