856539449 has 2 divisors, whose sum is σ = 856539450. Its totient is φ = 856539448.

The previous prime is 856539443. The next prime is 856539511. The reversal of 856539449 is 944935658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 796368400 + 60171049 = 28220^2 + 7757^2 .

It is a cyclic number.

It is not a de Polignac number, because 856539449 - 2⁸ = 856539193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 856539449.

It is not a weakly prime, because it can be changed into another prime (856539443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428269724 + 428269725.

It is an arithmetic number, because the mean of its divisors is an integer number (428269725).

Almost surely, 2^856539449 is an apocalyptic number.

It is an amenable number.

856539449 is a deficient number, since it is larger than the sum of its proper divisors (1).

856539449 is an equidigital number, since it uses as much as digits as its factorization.

856539449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4665600, while the sum is 53.

The square root of 856539449 is about 29266.6952182852. The cubic root of 856539449 is about 949.6912936013.

The spelling of 856539449 in words is "eight hundred fifty-six million, five hundred thirty-nine thousand, four hundred forty-nine".