840581317 has 2 divisors, whose sum is σ = 840581318. Its totient is φ = 840581316.

The previous prime is 840581309. The next prime is 840581333. The reversal of 840581317 is 713185048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 823058721 + 17522596 = 28689^2 + 4186^2 .

It is a cyclic number.

It is not a de Polignac number, because 840581317 - 2³ = 840581309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840581387) 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, 420290658 + 420290659.

It is an arithmetic number, because the mean of its divisors is an integer number (420290659).

Almost surely, 2^840581317 is an apocalyptic number.

It is an amenable number.

840581317 is a deficient number, since it is larger than the sum of its proper divisors (1).

840581317 is an equidigital number, since it uses as much as digits as its factorization.

840581317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 840581317 is about 28992.7804289275. The cubic root of 840581317 is about 943.7564026757.

The spelling of 840581317 in words is "eight hundred forty million, five hundred eighty-one thousand, three hundred seventeen".