28642765 has 4 divisors (see below), whose sum is σ = 34371324. Its totient is φ = 22914208.

The previous prime is 28642759. The next prime is 28642769. The reversal of 28642765 is 56724682.

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 22099401 + 6543364 = 4701^2 + 2558^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28642765 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 not an unprimeable number, because it can be changed into a prime (28642769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2864272 + ... + 2864281.

It is an arithmetic number, because the mean of its divisors is an integer number (8592831).

Almost surely, 2^28642765 is an apocalyptic number.

It is an amenable number.

28642765 is a deficient number, since it is larger than the sum of its proper divisors (5728559).

28642765 is an equidigital number, since it uses as much as digits as its factorization.

28642765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5728558.

The product of its digits is 161280, while the sum is 40.

The square root of 28642765 is about 5351.8935901230. The cubic root of 28642765 is about 305.9649275593.

The spelling of 28642765 in words is "twenty-eight million, six hundred forty-two thousand, seven hundred sixty-five".