28665308765 has 8 divisors (see below), whose sum is σ = 34427504088. Its totient is φ = 22912824640.

The previous prime is 28665308729. The next prime is 28665308783. The reversal of 28665308765 is 56780356682.

It can be written as a sum of positive squares in 4 ways, for example, as 9927531769 + 18737776996 = 99637^2 + 136886^2 .

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

It is not a de Polignac number, because 28665308765 - 2⁸ = 28665308509 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 28665308765.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2421302 + ... + 2433111.

It is an arithmetic number, because the mean of its divisors is an integer number (4303438011).

Almost surely, 2^28665308765 is an apocalyptic number.

It is an amenable number.

28665308765 is a deficient number, since it is larger than the sum of its proper divisors (5762195323).

28665308765 is a wasteful number, since it uses less digits than its factorization.

28665308765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4855599.

The product of its (nonzero) digits is 14515200, while the sum is 56.

The spelling of 28665308765 in words is "twenty-eight billion, six hundred sixty-five million, three hundred eight thousand, seven hundred sixty-five".