28805537 has 4 divisors (see below), whose sum is σ = 28951956. Its totient is φ = 28659120.

The previous prime is 28805527. The next prime is 28805561. The reversal of 28805537 is 73550882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73550882 = 2 ⋅36775441.

It can be written as a sum of positive squares in 2 ways, for example, as 24960016 + 3845521 = 4996^2 + 1961^2 .

It is a cyclic number.

It is not a de Polignac number, because 28805537 - 2⁴ = 28805521 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28805537.

It is not an unprimeable number, because it can be changed into a prime (28805527) 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, 72914 + ... + 73307.

It is an arithmetic number, because the mean of its divisors is an integer number (7237989).

Almost surely, 2^28805537 is an apocalyptic number.

It is an amenable number.

28805537 is a deficient number, since it is larger than the sum of its proper divisors (146419).

28805537 is a wasteful number, since it uses less digits than its factorization.

28805537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146418.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 28805537 is about 5367.0790007228. The cubic root of 28805537 is about 306.5434154733.

The spelling of 28805537 in words is "twenty-eight million, eight hundred five thousand, five hundred thirty-seven".