28317605 has 4 divisors (see below), whose sum is σ = 33981132. Its totient is φ = 22654080.

The previous prime is 28317587. The next prime is 28317637. The reversal of 28317605 is 50671382.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50671382 = 2 ⋅25335691.

It can be written as a sum of positive squares in 2 ways, for example, as 9229444 + 19088161 = 3038^2 + 4369^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28317605 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2831756 + ... + 2831765.

It is an arithmetic number, because the mean of its divisors is an integer number (8495283).

Almost surely, 2^28317605 is an apocalyptic number.

It is an amenable number.

28317605 is a deficient number, since it is larger than the sum of its proper divisors (5663527).

28317605 is an equidigital number, since it uses as much as digits as its factorization.

28317605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5663526.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 28317605 is about 5321.4288494727. The cubic root of 28317605 is about 304.8027211210.

Adding to 28317605 its reverse (50671382), we get a palindrome (78988987).

The spelling of 28317605 in words is "twenty-eight million, three hundred seventeen thousand, six hundred five".