28216659 has 4 divisors (see below), whose sum is σ = 37622216. Its totient is φ = 18811104.

The previous prime is 28216631. The next prime is 28216663. The reversal of 28216659 is 95661282.

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

It is not a de Polignac number, because 28216659 - 2⁵ = 28216627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28216679) 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, 4702774 + ... + 4702779.

It is an arithmetic number, because the mean of its divisors is an integer number (9405554).

Almost surely, 2^28216659 is an apocalyptic number.

28216659 is a deficient number, since it is larger than the sum of its proper divisors (9405557).

28216659 is an equidigital number, since it uses as much as digits as its factorization.

28216659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9405556.

The product of its digits is 51840, while the sum is 39.

The square root of 28216659 is about 5311.9355229521. The cubic root of 28216659 is about 304.4401051303.

The spelling of 28216659 in words is "twenty-eight million, two hundred sixteen thousand, six hundred fifty-nine".