28130231 has 2 divisors, whose sum is σ = 28130232. Its totient is φ = 28130230.

The previous prime is 28130209. The next prime is 28130251. The reversal of 28130231 is 13203182.

It is an a-pointer prime, because the next prime (28130251) can be obtained adding 28130231 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28130231 is a prime.

It is a super-2 number, since 2×28130231² = 1582619792226722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28130251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14065115 + 14065116.

It is an arithmetic number, because the mean of its divisors is an integer number (14065116).

Almost surely, 2^28130231 is an apocalyptic number.

28130231 is a deficient number, since it is larger than the sum of its proper divisors (1).

28130231 is an equidigital number, since it uses as much as digits as its factorization.

28130231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 28130231 is about 5303.7940193790. The cubic root of 28130231 is about 304.1289525350.

The spelling of 28130231 in words is "twenty-eight million, one hundred thirty thousand, two hundred thirty-one".