28917809 has 8 divisors (see below), whose sum is σ = 29304000. Its totient is φ = 28534032.

The previous prime is 28917797. The next prime is 28917821. The reversal of 28917809 is 90871982.

It is an interprime number because it is at equal distance from previous prime (28917797) and next prime (28917821).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28917809 - 2¹⁶ = 28852273 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28917809.

It is not an unprimeable number, because it can be changed into a prime (28917839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38762 + ... + 39500.

It is an arithmetic number, because the mean of its divisors is an integer number (3663000).

Almost surely, 2^28917809 is an apocalyptic number.

It is an amenable number.

28917809 is a deficient number, since it is larger than the sum of its proper divisors (386191).

28917809 is a wasteful number, since it uses less digits than its factorization.

28917809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1207.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 28917809 is about 5377.5281496241. The cubic root of 28917809 is about 306.9411587441.

The spelling of 28917809 in words is "twenty-eight million, nine hundred seventeen thousand, eight hundred nine".