28204765 has 4 divisors (see below), whose sum is σ = 33845724. Its totient is φ = 22563808.

The previous prime is 28204741. The next prime is 28204777. The reversal of 28204765 is 56740282.

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 6095961 + 22108804 = 2469^2 + 4702^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28204765 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 28204765.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2820472 + ... + 2820481.

It is an arithmetic number, because the mean of its divisors is an integer number (8461431).

Almost surely, 2^28204765 is an apocalyptic number.

It is an amenable number.

28204765 is a deficient number, since it is larger than the sum of its proper divisors (5640959).

28204765 is an equidigital number, since it uses as much as digits as its factorization.

28204765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5640958.

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 28204765 is about 5310.8158506956. The cubic root of 28204765 is about 304.3973228445.

The spelling of 28204765 in words is "twenty-eight million, two hundred four thousand, seven hundred sixty-five".