28390288 has 20 divisors (see below), whose sum is σ = 55627020. Its totient is φ = 14034944.

The previous prime is 28390283. The next prime is 28390301. The reversal of 28390288 is 88209382.

It can be written as a sum of positive squares in 2 ways, for example, as 5234944 + 23155344 = 2288^2 + 4812^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28390288.

It is not an unprimeable number, because it can be changed into a prime (28390283) 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 3 ways as a sum of consecutive naturals, for example, 8545 + ... + 11392.

It is an arithmetic number, because the mean of its divisors is an integer number (2781351).

Almost surely, 2^28390288 is an apocalyptic number.

It is an amenable number.

28390288 is a deficient number, since it is larger than the sum of its proper divisors (27236732).

28390288 is a wasteful number, since it uses less digits than its factorization.

28390288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20034 (or 20028 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 28390288 is about 5328.2537477113. The cubic root of 28390288 is about 305.0632781008.

The spelling of 28390288 in words is "twenty-eight million, three hundred ninety thousand, two hundred eighty-eight".