28171249 has 8 divisors (see below), whose sum is σ = 28789992. Its totient is φ = 27555840.

The previous prime is 28171237. The next prime is 28171271. The reversal of 28171249 is 94217182.

It can be written as a sum of positive squares in 4 ways, for example, as 8208225 + 19963024 = 2865^2 + 4468^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28171249 - 2⁵ = 28171217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28171229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23857 + ... + 25009.

It is an arithmetic number, because the mean of its divisors is an integer number (3598749).

Almost surely, 2^28171249 is an apocalyptic number.

It is an amenable number.

28171249 is a deficient number, since it is larger than the sum of its proper divisors (618743).

28171249 is a wasteful number, since it uses less digits than its factorization.

28171249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1667.

The product of its digits is 8064, while the sum is 34.

The square root of 28171249 is about 5307.6594653387. The cubic root of 28171249 is about 304.2767022749.

The spelling of 28171249 in words is "twenty-eight million, one hundred seventy-one thousand, two hundred forty-nine".