28008909 has 20 divisors (see below), whose sum is σ = 42042176. Its totient is φ = 18659484.

The previous prime is 28008901. The next prime is 28008919. The reversal of 28008909 is 90980082.

It is not a de Polignac number, because 28008909 - 2³ = 28008901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28008901) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18972 + ... + 20394.

Almost surely, 2^28008909 is an apocalyptic number.

It is an amenable number.

28008909 is a deficient number, since it is larger than the sum of its proper divisors (14033267).

28008909 is an frugal number, since it uses more digits than its factorization.

28008909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450 (or 1426 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 28008909 is about 5292.3443765500. The cubic root of 28008909 is about 303.6910996905.

The spelling of 28008909 in words is "twenty-eight million, eight thousand, nine hundred nine".