495809 has 4 divisors (see below), whose sum is σ = 500820. Its totient is φ = 490800.

The previous prime is 495799. The next prime is 495821. The reversal of 495809 is 908594.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908594 = 2 ⋅454297.

It can be written as a sum of positive squares in 2 ways, for example, as 485809 + 10000 = 697^2 + 100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-495809 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (495829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2354 + ... + 2555.

It is an arithmetic number, because the mean of its divisors is an integer number (125205).

2⁴⁹⁵⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

495809 is a deficient number, since it is larger than the sum of its proper divisors (5011).

495809 is a wasteful number, since it uses less digits than its factorization.

495809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5010.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 495809 is about 704.1370605216. The cubic root of 495809 is about 79.1476701727.

The spelling of 495809 in words is "four hundred ninety-five thousand, eight hundred nine".