28355249 has 4 divisors (see below), whose sum is σ = 30536436. Its totient is φ = 26174064.

The previous prime is 28355237. The next prime is 28355263. The reversal of 28355249 is 94255382.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15880225 + 12475024 = 3985^2 + 3532^2 .

It is a cyclic number.

It is not a de Polignac number, because 28355249 - 2²⁰ = 27306673 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28325249) 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, 1090574 + ... + 1090599.

It is an arithmetic number, because the mean of its divisors is an integer number (7634109).

Almost surely, 2^28355249 is an apocalyptic number.

It is an amenable number.

28355249 is a deficient number, since it is larger than the sum of its proper divisors (2181187).

28355249 is a wasteful number, since it uses less digits than its factorization.

28355249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2181186.

The product of its digits is 86400, while the sum is 38.

The square root of 28355249 is about 5324.9646947186. The cubic root of 28355249 is about 304.9377244527.

The spelling of 28355249 in words is "twenty-eight million, three hundred fifty-five thousand, two hundred forty-nine".