28009287 has 32 divisors (see below), whose sum is σ = 44352000. Its totient is φ = 17418240.

The previous prime is 28009231. The next prime is 28009291. The reversal of 28009287 is 78290082.

It is not a de Polignac number, because 28009287 - 2¹⁰ = 28008263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28002287) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36039 + ... + 36807.

It is an arithmetic number, because the mean of its divisors is an integer number (1386000).

Almost surely, 2^28009287 is an apocalyptic number.

28009287 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28009287 is a deficient number, since it is larger than the sum of its proper divisors (16342713).

28009287 is a wasteful number, since it uses less digits than its factorization.

28009287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868 (or 862 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 28009287 is about 5292.3800883912. The cubic root of 28009287 is about 303.6924658596.

The spelling of 28009287 in words is "twenty-eight million, nine thousand, two hundred eighty-seven".