840078017 has 2 divisors, whose sum is σ = 840078018. Its totient is φ = 840078016.

The previous prime is 840077993. The next prime is 840078067. The reversal of 840078017 is 710870048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 651729841 + 188348176 = 25529^2 + 13724^2 .

It is a cyclic number.

It is not a de Polignac number, because 840078017 - 2¹⁴ = 840061633 is a prime.

It is not a weakly prime, because it can be changed into another prime (840078067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420039008 + 420039009.

It is an arithmetic number, because the mean of its divisors is an integer number (420039009).

Almost surely, 2^840078017 is an apocalyptic number.

It is an amenable number.

840078017 is a deficient number, since it is larger than the sum of its proper divisors (1).

840078017 is an equidigital number, since it uses as much as digits as its factorization.

840078017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 840078017 is about 28984.0993822475. The cubic root of 840078017 is about 943.5680062964.

The spelling of 840078017 in words is "eight hundred forty million, seventy-eight thousand, seventeen".