28704029 has 4 divisors (see below), whose sum is σ = 28774620. Its totient is φ = 28633440.

The previous prime is 28704017. The next prime is 28704061. The reversal of 28704029 is 92040782.

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 20160100 + 8543929 = 4490^2 + 2923^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28704029 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28703986 and 28704004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28704089) by changing a digit.

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, 34682 + ... + 35499.

It is an arithmetic number, because the mean of its divisors is an integer number (7193655).

Almost surely, 2^28704029 is an apocalyptic number.

It is an amenable number.

28704029 is a deficient number, since it is larger than the sum of its proper divisors (70591).

28704029 is an equidigital number, since it uses as much as digits as its factorization.

28704029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70590.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 28704029 is about 5357.6141145103. The cubic root of 28704029 is about 306.1829149741.

The spelling of 28704029 in words is "twenty-eight million, seven hundred four thousand, twenty-nine".