28772005 has 8 divisors (see below), whose sum is σ = 34675992. Its totient is φ = 22917888.

The previous prime is 28771997. The next prime is 28772063. The reversal of 28772005 is 50027782.

It can be written as a sum of positive squares in 4 ways, for example, as 5094049 + 23677956 = 2257^2 + 4866^2 .

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 28772005 - 2³ = 28771997 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11184 + ... + 13513.

It is an arithmetic number, because the mean of its divisors is an integer number (4334499).

Almost surely, 2^28772005 is an apocalyptic number.

It is an amenable number.

28772005 is a deficient number, since it is larger than the sum of its proper divisors (5903987).

28772005 is a wasteful number, since it uses less digits than its factorization.

28772005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24935.

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 28772005 is about 5363.9542317212. The cubic root of 28772005 is about 306.4244220899.

Adding to 28772005 its reverse (50027782), we get a palindrome (78799787).

The spelling of 28772005 in words is "twenty-eight million, seven hundred seventy-two thousand, five".