28288231 has 2 divisors, whose sum is σ = 28288232. Its totient is φ = 28288230.

The previous prime is 28288193. The next prime is 28288243. The reversal of 28288231 is 13288282.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28288231 - 2¹¹ = 28286183 is a prime.

It is a super-2 number, since 2×28288231² = 1600448026218722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28288261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14144115 + 14144116.

It is an arithmetic number, because the mean of its divisors is an integer number (14144116).

Almost surely, 2^28288231 is an apocalyptic number.

28288231 is a deficient number, since it is larger than the sum of its proper divisors (1).

28288231 is an equidigital number, since it uses as much as digits as its factorization.

28288231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12288, while the sum is 34.

The square root of 28288231 is about 5318.6681603574. The cubic root of 28288231 is about 304.6972935059.

The spelling of 28288231 in words is "twenty-eight million, two hundred eighty-eight thousand, two hundred thirty-one".