840442009 has 8 divisors (see below), whose sum is σ = 938168352. Its totient is φ = 746269440.

The previous prime is 840441983. The next prime is 840442027. The reversal of 840442009 is 900244048.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 840442009 - 2⁵ = 840441977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (840442709) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 887944 + ... + 888889.

It is an arithmetic number, because the mean of its divisors is an integer number (117271044).

Almost surely, 2^840442009 is an apocalyptic number.

It is an amenable number.

840442009 is a deficient number, since it is larger than the sum of its proper divisors (97726343).

840442009 is a wasteful number, since it uses less digits than its factorization.

840442009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1776887.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 840442009 is about 28990.3778692172. The cubic root of 840442009 is about 943.7042641228.

The spelling of 840442009 in words is "eight hundred forty million, four hundred forty-two thousand, nine".