28551317 has 4 divisors (see below), whose sum is σ = 28562220. Its totient is φ = 28540416.

The previous prime is 28551287. The next prime is 28551323. The reversal of 28551317 is 71315582.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8561476 + 19989841 = 2926^2 + 4471^2 .

It is a cyclic number.

It is not a de Polignac number, because 28551317 - 2¹⁶ = 28485781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28551377) 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, 1109 + ... + 7637.

It is an arithmetic number, because the mean of its divisors is an integer number (7140555).

Almost surely, 2^28551317 is an apocalyptic number.

It is an amenable number.

28551317 is a deficient number, since it is larger than the sum of its proper divisors (10903).

28551317 is an equidigital number, since it uses as much as digits as its factorization.

28551317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10902.

The product of its digits is 8400, while the sum is 32.

The square root of 28551317 is about 5343.3432418290. The cubic root of 28551317 is about 305.6389614637.

Adding to 28551317 its reverse (71315582), we get a palindrome (99866899).

The spelling of 28551317 in words is "twenty-eight million, five hundred fifty-one thousand, three hundred seventeen".