840358081 has 2 divisors, whose sum is σ = 840358082. Its totient is φ = 840358080.

The previous prime is 840358039. The next prime is 840358109. The reversal of 840358081 is 180853048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 836135056 + 4223025 = 28916^2 + 2055^2 .

It is a cyclic number.

It is not a de Polignac number, because 840358081 - 2⁷ = 840357953 is a prime.

It is a super-2 number, since 2×840358081² = 1412403408604005122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 840358081.

It is not a weakly prime, because it can be changed into another prime (840358031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420179040 + 420179041.

It is an arithmetic number, because the mean of its divisors is an integer number (420179041).

Almost surely, 2^840358081 is an apocalyptic number.

It is an amenable number.

840358081 is a deficient number, since it is larger than the sum of its proper divisors (1).

840358081 is an equidigital number, since it uses as much as digits as its factorization.

840358081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 840358081 is about 28988.9303183129. The cubic root of 840358081 is about 943.6728497610.

The spelling of 840358081 in words is "eight hundred forty million, three hundred fifty-eight thousand, eighty-one".