28312609 has 16 divisors (see below), whose sum is σ = 32054400. Its totient is φ = 24858768.

The previous prime is 28312607. The next prime is 28312621. The reversal of 28312609 is 90621382.

It is not a de Polignac number, because 28312609 - 2¹ = 28312607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28312607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 158082 + ... + 158260.

It is an arithmetic number, because the mean of its divisors is an integer number (2003400).

Almost surely, 2^28312609 is an apocalyptic number.

It is an amenable number.

28312609 is a deficient number, since it is larger than the sum of its proper divisors (3741791).

28312609 is an equidigital number, since it uses as much as digits as its factorization.

28312609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 28312609 is about 5320.9594059718. The cubic root of 28312609 is about 304.7847948879.

The spelling of 28312609 in words is "twenty-eight million, three hundred twelve thousand, six hundred nine".