28043237 has 4 divisors (see below), whose sum is σ = 28085580. Its totient is φ = 28000896.

The previous prime is 28043227. The next prime is 28043243. The reversal of 28043237 is 73234082.

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 6522916 + 21520321 = 2554^2 + 4639^2 .

It is a cyclic number.

It is not a de Polignac number, because 28043237 - 2⁶ = 28043173 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 (28043207) 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 3 ways as a sum of consecutive naturals, for example, 20162 + ... + 21507.

It is an arithmetic number, because the mean of its divisors is an integer number (7021395).

Almost surely, 2^28043237 is an apocalyptic number.

It is an amenable number.

28043237 is a deficient number, since it is larger than the sum of its proper divisors (42343).

28043237 is an equidigital number, since it uses as much as digits as its factorization.

28043237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42342.

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 28043237 is about 5295.5865586354. The cubic root of 28043237 is about 303.8151179916.

The spelling of 28043237 in words is "twenty-eight million, forty-three thousand, two hundred thirty-seven".