28505633 has 4 divisors (see below), whose sum is σ = 30698388. Its totient is φ = 26312880.

The previous prime is 28505627. The next prime is 28505639. The reversal of 28505633 is 33650582.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (28505627) and next prime (28505639).

It can be written as a sum of positive squares in 2 ways, for example, as 16589329 + 11916304 = 4073^2 + 3452^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28505633 is a prime.

It is a super-2 number, since 2×28505633² = 1625142225461378, which contains 22 as substring.

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 28505633.

It is not an unprimeable number, because it can be changed into a prime (28505639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096358 + ... + 1096383.

It is an arithmetic number, because the mean of its divisors is an integer number (7674597).

Almost surely, 2^28505633 is an apocalyptic number.

It is an amenable number.

28505633 is a deficient number, since it is larger than the sum of its proper divisors (2192755).

28505633 is a wasteful number, since it uses less digits than its factorization.

28505633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192754.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 28505633 is about 5339.0666787370. The cubic root of 28505633 is about 305.4758602416.

The spelling of 28505633 in words is "twenty-eight million, five hundred five thousand, six hundred thirty-three".