28684261 has 2 divisors, whose sum is σ = 28684262. Its totient is φ = 28684260.

The previous prime is 28684237. The next prime is 28684283. The reversal of 28684261 is 16248682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24940036 + 3744225 = 4994^2 + 1935^2 .

It is a cyclic number.

It is not a de Polignac number, because 28684261 - 2¹³ = 28676069 is a prime.

It is a super-2 number, since 2×28684261² = 1645573658232242, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28684261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28684211) 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, 14342130 + 14342131.

It is an arithmetic number, because the mean of its divisors is an integer number (14342131).

Almost surely, 2^28684261 is an apocalyptic number.

It is an amenable number.

28684261 is a deficient number, since it is larger than the sum of its proper divisors (1).

28684261 is an equidigital number, since it uses as much as digits as its factorization.

28684261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 37.

The square root of 28684261 is about 5355.7689457257. The cubic root of 28684261 is about 306.1126110939.

It can be divided in two parts, 286842 and 61, that added together give a triangular number (286903 = T₇₅₇).

The spelling of 28684261 in words is "twenty-eight million, six hundred eighty-four thousand, two hundred sixty-one".