840409013 has 2 divisors, whose sum is σ = 840409014. Its totient is φ = 840409012.

The previous prime is 840409001. The next prime is 840409027. The reversal of 840409013 is 310904048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 666775684 + 173633329 = 25822^2 + 13177^2 .

It is a cyclic number.

It is not a de Polignac number, because 840409013 - 2²⁰ = 839360437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840408013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420204506 + 420204507.

It is an arithmetic number, because the mean of its divisors is an integer number (420204507).

Almost surely, 2^840409013 is an apocalyptic number.

It is an amenable number.

840409013 is a deficient number, since it is larger than the sum of its proper divisors (1).

840409013 is an equidigital number, since it uses as much as digits as its factorization.

840409013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 840409013 is about 28989.8087782586. The cubic root of 840409013 is about 943.6919139257.

The spelling of 840409013 in words is "eight hundred forty million, four hundred nine thousand, thirteen".