28439289 has 32 divisors (see below), whose sum is σ = 43520000. Its totient is φ = 18347472.

The previous prime is 28439287. The next prime is 28439291. The reversal of 28439289 is 98293482.

It is an interprime number because it is at equal distance from previous prime (28439287) and next prime (28439291).

It is not a de Polignac number, because 28439289 - 2¹ = 28439287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28439287) 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, 142812 + ... + 143010.

It is an arithmetic number, because the mean of its divisors is an integer number (1360000).

Almost surely, 2^28439289 is an apocalyptic number.

It is an amenable number.

28439289 is a deficient number, since it is larger than the sum of its proper divisors (15080711).

28439289 is a wasteful number, since it uses less digits than its factorization.

28439289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354 (or 348 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 28439289 is about 5332.8499885146. The cubic root of 28439289 is about 305.2386880124.

The spelling of 28439289 in words is "twenty-eight million, four hundred thirty-nine thousand, two hundred eighty-nine".