840409005 has 16 divisors (see below), whose sum is σ = 1345699584. Its totient is φ = 447869760.

The previous prime is 840409001. The next prime is 840409013. The reversal of 840409005 is 500904048.

It is not a de Polignac number, because 840409005 - 2² = 840409001 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840409001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1206 + ... + 41015.

It is an arithmetic number, because the mean of its divisors is an integer number (84106224).

Almost surely, 2^840409005 is an apocalyptic number.

It is an amenable number.

840409005 is a deficient number, since it is larger than the sum of its proper divisors (505290579).

840409005 is a wasteful number, since it uses less digits than its factorization.

840409005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43556.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 840409005 is about 28989.8086402791. The cubic root of 840409005 is about 943.6919109313.

The spelling of 840409005 in words is "eight hundred forty million, four hundred nine thousand, five".