409806 has 16 divisors (see below), whose sum is σ = 910800. Its totient is φ = 136584.

The previous prime is 409781. The next prime is 409813. The reversal of 409806 is 608904.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 409806.

It is a congruent number.

It is an unprimeable number.

409806 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3741 + ... + 3848.

It is an arithmetic number, because the mean of its divisors is an integer number (56925).

2⁴⁰⁹⁸⁰⁶ is an apocalyptic number.

409806 is an abundant number, since it is smaller than the sum of its proper divisors (500994).

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

409806 is a wasteful number, since it uses less digits than its factorization.

409806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7600 (or 7594 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 409806 is about 640.1609172700. The cubic root of 409806 is about 74.2778693463.

The spelling of 409806 in words is "four hundred nine thousand, eight hundred six".