28040249 has 4 divisors (see below), whose sum is σ = 28424436. Its totient is φ = 27656064.

The previous prime is 28040239. The next prime is 28040261. The reversal of 28040249 is 94204082.

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 6091024 + 21949225 = 2468^2 + 4685^2 .

It is a cyclic number.

It is not a de Polignac number, because 28040249 - 2⁸ = 28039993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28040209) 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, 191984 + ... + 192129.

It is an arithmetic number, because the mean of its divisors is an integer number (7106109).

Almost surely, 2^28040249 is an apocalyptic number.

It is an amenable number.

28040249 is a deficient number, since it is larger than the sum of its proper divisors (384187).

28040249 is an equidigital number, since it uses as much as digits as its factorization.

28040249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384186.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 28040249 is about 5295.3044293978. The cubic root of 28040249 is about 303.8043271329.

The spelling of 28040249 in words is "twenty-eight million, forty thousand, two hundred forty-nine".