28006565 has 8 divisors (see below), whose sum is σ = 35584920. Its totient is φ = 21087232.

The previous prime is 28006543. The next prime is 28006591. The reversal of 28006565 is 56560082.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6235009 + 21771556 = 2497^2 + 4666^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28006565 - 2⁸ = 28006309 is a prime.

It is a super-3 number, since 3×28006565³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 164660 + ... + 164829.

It is an arithmetic number, because the mean of its divisors is an integer number (4448115).

Almost surely, 2^28006565 is an apocalyptic number.

It is an amenable number.

28006565 is a deficient number, since it is larger than the sum of its proper divisors (7578355).

28006565 is a wasteful number, since it uses less digits than its factorization.

28006565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329511.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 28006565 is about 5292.1229199632. The cubic root of 28006565 is about 303.6826277218.

The spelling of 28006565 in words is "twenty-eight million, six thousand, five hundred sixty-five".