409818 has 16 divisors (see below), whose sum is σ = 826560. Its totient is φ = 135456.

The previous prime is 409817. The next prime is 409823. The reversal of 409818 is 818904.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (409813) 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, 798 + ... + 1206.

It is an arithmetic number, because the mean of its divisors is an integer number (51660).

2⁴⁰⁹⁸¹⁸ is an apocalyptic number.

409818 is an abundant number, since it is smaller than the sum of its proper divisors (416742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

409818 is a wasteful number, since it uses less digits than its factorization.

409818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 409818 is about 640.1702898448. The cubic root of 409818 is about 74.2785943444.

The spelling of 409818 in words is "four hundred nine thousand, eight hundred eighteen".