28916231 has 2 divisors, whose sum is σ = 28916232. Its totient is φ = 28916230.

The previous prime is 28916213. The next prime is 28916263. The reversal of 28916231 is 13261982.

Together with previous prime (28916213) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (28916263) can be obtained adding 28916231 to its sum of digits (32).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28916231 is a prime.

It is a super-2 number, since 2×28916231² = 1672296830490722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28946231) 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 as a sum of consecutive naturals, namely, 14458115 + 14458116.

It is an arithmetic number, because the mean of its divisors is an integer number (14458116).

Almost surely, 2^28916231 is an apocalyptic number.

28916231 is a deficient number, since it is larger than the sum of its proper divisors (1).

28916231 is an equidigital number, since it uses as much as digits as its factorization.

28916231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 32.

The square root of 28916231 is about 5377.3814259359. The cubic root of 28916231 is about 306.9355755416.

The spelling of 28916231 in words is "twenty-eight million, nine hundred sixteen thousand, two hundred thirty-one".