409856 has 18 divisors (see below), whose sum is σ = 818622. Its totient is φ = 204800.

The previous prime is 409841. The next prime is 409861. The reversal of 409856 is 658904.

It can be written as a sum of positive squares in only one way, i.e., 409600 + 256 = 640^2 + 16^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a nialpdrome in base 16.

It is an unprimeable number.

409856 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 as a sum of consecutive naturals, namely, 545 + ... + 1056.

It is an arithmetic number, because the mean of its divisors is an integer number (45479).

2⁴⁰⁹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

409856 is a deficient number, since it is larger than the sum of its proper divisors (408766).

409856 is an equidigital number, since it uses as much as digits as its factorization.

409856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1617 (or 1603 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 409856 is about 640.1999687598. The cubic root of 409856 is about 74.2808900784.

The spelling of 409856 in words is "four hundred nine thousand, eight hundred fifty-six".