840408013 has 2 divisors, whose sum is σ = 840408014. Its totient is φ = 840408012.

The previous prime is 840407983. The next prime is 840408029. The reversal of 840408013 is 310804048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 477772164 + 362635849 = 21858^2 + 19043^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840408013 is a prime.

It is equal to p_43115257 and since 840408013 and 43115257 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840408113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420204006 + 420204007.

It is an arithmetic number, because the mean of its divisors is an integer number (420204007).

Almost surely, 2^840408013 is an apocalyptic number.

It is an amenable number.

840408013 is a deficient number, since it is larger than the sum of its proper divisors (1).

840408013 is an equidigital number, since it uses as much as digits as its factorization.

840408013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 840408013 is about 28989.7915308130. The cubic root of 840408013 is about 943.6915396269.

The spelling of 840408013 in words is "eight hundred forty million, four hundred eight thousand, thirteen".