28387089 has 12 divisors (see below), whose sum is σ = 41182596. Its totient is φ = 18842112.

The previous prime is 28387087. The next prime is 28387091. The reversal of 28387089 is 98078382.

It is an interprime number because it is at equal distance from previous prime (28387087) and next prime (28387091).

It can be written as a sum of positive squares in 2 ways, for example, as 18558864 + 9828225 = 4308^2 + 3135^2 .

It is not a de Polignac number, because 28387089 - 2¹ = 28387087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28387081) 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 11 ways as a sum of consecutive naturals, for example, 4672 + ... + 8865.

It is an arithmetic number, because the mean of its divisors is an integer number (3431883).

Almost surely, 2^28387089 is an apocalyptic number.

It is an amenable number.

28387089 is a deficient number, since it is larger than the sum of its proper divisors (12795507).

28387089 is a wasteful number, since it uses less digits than its factorization.

28387089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13776 (or 13773 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 28387089 is about 5327.9535470948. The cubic root of 28387089 is about 305.0518195569.

The spelling of 28387089 in words is "twenty-eight million, three hundred eighty-seven thousand, eighty-nine".