428809 has 2 divisors, whose sum is σ = 428810. Its totient is φ = 428808.

The previous prime is 428807. The next prime is 428833. The reversal of 428809 is 908824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 299209 + 129600 = 547^2 + 360^2 .

It is a cyclic number.

It is not a de Polignac number, because 428809 - 2¹ = 428807 is a prime.

Together with 428807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (428801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214404 + 214405.

It is an arithmetic number, because the mean of its divisors is an integer number (214405).

2⁴²⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

428809 is a deficient number, since it is larger than the sum of its proper divisors (1).

428809 is an equidigital number, since it uses as much as digits as its factorization.

428809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 428809 is about 654.8350937450. The cubic root of 428809 is about 75.4086728128.

The spelling of 428809 in words is "four hundred twenty-eight thousand, eight hundred nine".