28987249 has 4 divisors (see below), whose sum is σ = 29137636. Its totient is φ = 28836864.

The previous prime is 28987207. The next prime is 28987253. The reversal of 28987249 is 94278982.

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 + 22896225 = 2468^2 + 4785^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28987249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28987649) 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, 74904 + ... + 75289.

It is an arithmetic number, because the mean of its divisors is an integer number (7284409).

Almost surely, 2^28987249 is an apocalyptic number.

It is an amenable number.

28987249 is a deficient number, since it is larger than the sum of its proper divisors (150387).

28987249 is a wasteful number, since it uses less digits than its factorization.

28987249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150386.

The product of its digits is 580608, while the sum is 49.

The square root of 28987249 is about 5383.9807763401. The cubic root of 28987249 is about 307.1866471032.

The spelling of 28987249 in words is "twenty-eight million, nine hundred eighty-seven thousand, two hundred forty-nine".