28716661 has 4 divisors (see below), whose sum is σ = 28727392. Its totient is φ = 28705932.

The previous prime is 28716643. The next prime is 28716683. The reversal of 28716661 is 16661782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28716661 - 2⁵ = 28716629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28716661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28716601) 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, 2296 + ... + 7918.

It is an arithmetic number, because the mean of its divisors is an integer number (7181848).

Almost surely, 2^28716661 is an apocalyptic number.

It is an amenable number.

28716661 is a deficient number, since it is larger than the sum of its proper divisors (10731).

28716661 is an equidigital number, since it uses as much as digits as its factorization.

28716661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10730.

The product of its digits is 24192, while the sum is 37.

The square root of 28716661 is about 5358.7928678015. The cubic root of 28716661 is about 306.2278231338.

The spelling of 28716661 in words is "twenty-eight million, seven hundred sixteen thousand, six hundred sixty-one".