28516231 has 2 divisors, whose sum is σ = 28516232. Its totient is φ = 28516230.

The previous prime is 28516217. The next prime is 28516247. The reversal of 28516231 is 13261582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28516231 - 2⁹ = 28515719 is a prime.

It is a super-2 number, since 2×28516231² = 1626350860890722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28516231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28516291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14258115 + 14258116.

It is an arithmetic number, because the mean of its divisors is an integer number (14258116).

Almost surely, 2^28516231 is an apocalyptic number.

28516231 is a deficient number, since it is larger than the sum of its proper divisors (1).

28516231 is an equidigital number, since it uses as much as digits as its factorization.

28516231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 28.

The square root of 28516231 is about 5340.0590820702. The cubic root of 28516231 is about 305.5137127839.

The spelling of 28516231 in words is "twenty-eight million, five hundred sixteen thousand, two hundred thirty-one".