28217687 has 4 divisors (see below), whose sum is σ = 28292520. Its totient is φ = 28142856.

The previous prime is 28217669. The next prime is 28217701. The reversal of 28217687 is 78671282.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28217687 - 2¹⁰ = 28216663 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 (28217627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36848 + ... + 37605.

It is an arithmetic number, because the mean of its divisors is an integer number (7073130).

Almost surely, 2^28217687 is an apocalyptic number.

28217687 is a deficient number, since it is larger than the sum of its proper divisors (74833).

28217687 is an equidigital number, since it uses as much as digits as its factorization.

28217687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74832.

The product of its digits is 75264, while the sum is 41.

The square root of 28217687 is about 5312.0322852935. The cubic root of 28217687 is about 304.4438022445.

The spelling of 28217687 in words is "twenty-eight million, two hundred seventeen thousand, six hundred eighty-seven".