440809 has 2 divisors, whose sum is σ = 440810. Its totient is φ = 440808.

The previous prime is 440807. The next prime is 440821. The reversal of 440809 is 908044.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 426409 + 14400 = 653^2 + 120^2 .

It is a cyclic number.

It is not a de Polignac number, because 440809 - 2¹ = 440807 is a prime.

Together with 440807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (440807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 220404 + 220405.

It is an arithmetic number, because the mean of its divisors is an integer number (220405).

2⁴⁴⁰⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

440809 is a deficient number, since it is larger than the sum of its proper divisors (1).

440809 is an equidigital number, since it uses as much as digits as its factorization.

440809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 440809 is about 663.9344847197. The cubic root of 440809 is about 76.1056356529.

The spelling of 440809 in words is "four hundred forty thousand, eight hundred nine".