28661765 has 16 divisors (see below), whose sum is σ = 38140416. Its totient is φ = 20500800.

The previous prime is 28661713. The next prime is 28661783. The reversal of 28661765 is 56716682.

It is not a de Polignac number, because 28661765 - 2²⁰ = 27613189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 917 + ... + 7626.

It is an arithmetic number, because the mean of its divisors is an integer number (2383776).

Almost surely, 2^28661765 is an apocalyptic number.

It is an amenable number.

28661765 is a deficient number, since it is larger than the sum of its proper divisors (9478651).

28661765 is a wasteful number, since it uses less digits than its factorization.

28661765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8620.

The product of its digits is 120960, while the sum is 41.

The square root of 28661765 is about 5353.6683685114. The cubic root of 28661765 is about 306.0325659162.

It can be divided in two parts, 286617 and 65, that added together give a palindrome (286682).

The spelling of 28661765 in words is "twenty-eight million, six hundred sixty-one thousand, seven hundred sixty-five".