28005172 has 12 divisors (see below), whose sum is σ = 52779076. Its totient is φ = 12925440.

The previous prime is 28005163. The next prime is 28005199. The reversal of 28005172 is 27150082.

It can be written as a sum of positive squares in 2 ways, for example, as 2643876 + 25361296 = 1626^2 + 5036^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269229 + ... + 269332.

Almost surely, 2^28005172 is an apocalyptic number.

It is an amenable number.

28005172 is a deficient number, since it is larger than the sum of its proper divisors (24773904).

28005172 is a wasteful number, since it uses less digits than its factorization.

28005172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538578 (or 538576 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 28005172 is about 5291.9913076270. The cubic root of 28005172 is about 303.6775927486.

The spelling of 28005172 in words is "twenty-eight million, five thousand, one hundred seventy-two".