28717189 has 6 divisors (see below), whose sum is σ = 30308550. Its totient is φ = 27205416.

The previous prime is 28717187. The next prime is 28717193. The reversal of 28717189 is 98171782.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 28708164 + 9025 = 5358^2 + 95^2 .

It is not a de Polignac number, because 28717189 - 2¹ = 28717187 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 (28717181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 39414 + ... + 40135.

It is an arithmetic number, because the mean of its divisors is an integer number (5051425).

Almost surely, 2^28717189 is an apocalyptic number.

It is an amenable number.

28717189 is a deficient number, since it is larger than the sum of its proper divisors (1591361).

28717189 is an equidigital number, since it uses as much as digits as its factorization.

28717189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79587 (or 79568 counting only the distinct ones).

The product of its digits is 56448, while the sum is 43.

The square root of 28717189 is about 5358.8421324014. The cubic root of 28717189 is about 306.2296999456.

The spelling of 28717189 in words is "twenty-eight million, seven hundred seventeen thousand, one hundred eighty-nine".