28987843 has 4 divisors (see below), whose sum is σ = 30248208. Its totient is φ = 27727480.

The previous prime is 28987837. The next prime is 28987853. The reversal of 28987843 is 34878982.

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

It is a cyclic number.

It is not a de Polignac number, because 28987843 - 2¹³ = 28979651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28987823) by changing a digit.

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, 630148 + ... + 630193.

It is an arithmetic number, because the mean of its divisors is an integer number (7562052).

Almost surely, 2^28987843 is an apocalyptic number.

28987843 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

28987843 is a deficient number, since it is larger than the sum of its proper divisors (1260365).

28987843 is a wasteful number, since it uses less digits than its factorization.

28987843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260364.

The product of its digits is 774144, while the sum is 49.

The square root of 28987843 is about 5384.0359397017. The cubic root of 28987843 is about 307.1887453548.

The spelling of 28987843 in words is "twenty-eight million, nine hundred eighty-seven thousand, eight hundred forty-three".