28647831 has 4 divisors (see below), whose sum is σ = 38197112. Its totient is φ = 19098552.

The previous prime is 28647809. The next prime is 28647833. The reversal of 28647831 is 13874682.

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

It is not a de Polignac number, because 28647831 - 2⁵ = 28647799 is a prime.

It is a super-2 number, since 2×28647831² = 1641396442009122, 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 28647831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28647833) 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, 4774636 + ... + 4774641.

It is an arithmetic number, because the mean of its divisors is an integer number (9549278).

Almost surely, 2^28647831 is an apocalyptic number.

28647831 is a deficient number, since it is larger than the sum of its proper divisors (9549281).

28647831 is an equidigital number, since it uses as much as digits as its factorization.

28647831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9549280.

The product of its digits is 64512, while the sum is 39.

The square root of 28647831 is about 5352.3668596239. The cubic root of 28647831 is about 305.9829650049.

The spelling of 28647831 in words is "twenty-eight million, six hundred forty-seven thousand, eight hundred thirty-one".