865543249 has 2 divisors, whose sum is σ = 865543250. Its totient is φ = 865543248.

The previous prime is 865543247. The next prime is 865543297. The reversal of 865543249 is 942345568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 853516225 + 12027024 = 29215^2 + 3468^2 .

It is a cyclic number.

It is not a de Polignac number, because 865543249 - 2¹ = 865543247 is a prime.

It is a super-3 number, since 3×865543249³ (a number of 28 digits) contains 333 as substring.

Together with 865543247, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 865543199 and 865543208.

It is not a weakly prime, because it can be changed into another prime (865543241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432771624 + 432771625.

It is an arithmetic number, because the mean of its divisors is an integer number (432771625).

Almost surely, 2^865543249 is an apocalyptic number.

It is an amenable number.

865543249 is a deficient number, since it is larger than the sum of its proper divisors (1).

865543249 is an equidigital number, since it uses as much as digits as its factorization.

865543249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1036800, while the sum is 46.

The square root of 865543249 is about 29420.1164001776. The cubic root of 865543249 is about 953.0073668230.

The spelling of 865543249 in words is "eight hundred sixty-five million, five hundred forty-three thousand, two hundred forty-nine".