28243261 has 2 divisors, whose sum is σ = 28243262. Its totient is φ = 28243260.

The previous prime is 28243231. The next prime is 28243283. The reversal of 28243261 is 16234282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26977636 + 1265625 = 5194^2 + 1125^2 .

It is a cyclic number.

It is not a de Polignac number, because 28243261 - 2⁷ = 28243133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28243231) 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, 14121630 + 14121631.

It is an arithmetic number, because the mean of its divisors is an integer number (14121631).

Almost surely, 2^28243261 is an apocalyptic number.

It is an amenable number.

28243261 is a deficient number, since it is larger than the sum of its proper divisors (1).

28243261 is an equidigital number, since it uses as much as digits as its factorization.

28243261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 28.

The square root of 28243261 is about 5314.4389167625. The cubic root of 28243261 is about 304.5357480614.

The spelling of 28243261 in words is "twenty-eight million, two hundred forty-three thousand, two hundred sixty-one".