409909 has 2 divisors, whose sum is σ = 409910. Its totient is φ = 409908.

The previous prime is 409901. The next prime is 409933. The reversal of 409909 is 909904.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 378225 + 31684 = 615^2 + 178^2 .

It is a cyclic number.

It is not a de Polignac number, because 409909 - 2³ = 409901 is a prime.

It is a nialpdrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (409901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204954 + 204955.

It is an arithmetic number, because the mean of its divisors is an integer number (204955).

2⁴⁰⁹⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

409909 is a deficient number, since it is larger than the sum of its proper divisors (1).

409909 is an equidigital number, since it uses as much as digits as its factorization.

409909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 409909 is about 640.2413607383. The cubic root of 409909 is about 74.2840917862.

The spelling of 409909 in words is "four hundred nine thousand, nine hundred nine".