28149565 has 4 divisors (see below), whose sum is σ = 33779484. Its totient is φ = 22519648.

The previous prime is 28149559. The next prime is 28149593. The reversal of 28149565 is 56594182.

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 3755844 + 24393721 = 1938^2 + 4939^2 .

It is a cyclic number.

It is not a de Polignac number, because 28149565 - 2³ = 28149557 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2814952 + ... + 2814961.

It is an arithmetic number, because the mean of its divisors is an integer number (8444871).

Almost surely, 2^28149565 is an apocalyptic number.

It is an amenable number.

28149565 is a deficient number, since it is larger than the sum of its proper divisors (5629919).

28149565 is an equidigital number, since it uses as much as digits as its factorization.

28149565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5629918.

The product of its digits is 86400, while the sum is 40.

The square root of 28149565 is about 5305.6163638167. The cubic root of 28149565 is about 304.1986128536.

The spelling of 28149565 in words is "twenty-eight million, one hundred forty-nine thousand, five hundred sixty-five".