404309 has 2 divisors, whose sum is σ = 404310. Its totient is φ = 404308.

The previous prime is 404291. The next prime is 404321. The reversal of 404309 is 903404.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 334084 + 70225 = 578^2 + 265^2 .

It is a cyclic number.

It is not a de Polignac number, because 404309 - 2¹⁶ = 338773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202154 + 202155.

It is an arithmetic number, because the mean of its divisors is an integer number (202155).

2⁴⁰⁴³⁰⁹ is an apocalyptic number.

It is an amenable number.

404309 is a deficient number, since it is larger than the sum of its proper divisors (1).

404309 is an equidigital number, since it uses as much as digits as its factorization.

404309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 404309 is about 635.8529704263. The cubic root of 404309 is about 73.9442604359.

The spelling of 404309 in words is "four hundred four thousand, three hundred nine".