28004705 has 8 divisors (see below), whose sum is σ = 33647400. Its totient is φ = 22375936.

The previous prime is 28004693. The next prime is 28004707. The reversal of 28004705 is 50740082.

It can be written as a sum of positive squares in 4 ways, for example, as 1882384 + 26122321 = 1372^2 + 5111^2 .

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 28004705 - 2¹⁴ = 27988321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28004707) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1631 + ... + 7659.

It is an arithmetic number, because the mean of its divisors is an integer number (4205925).

Almost surely, 2^28004705 is an apocalyptic number.

It is an amenable number.

28004705 is a deficient number, since it is larger than the sum of its proper divisors (5642695).

28004705 is an equidigital number, since it uses as much as digits as its factorization.

28004705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6963.

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 28004705 is about 5291.9471841658. The cubic root of 28004705 is about 303.6759047482.

Adding to 28004705 its reverse (50740082), we get a palindrome (78744787).

The spelling of 28004705 in words is "twenty-eight million, four thousand, seven hundred five".