618809 has 4 divisors (see below), whose sum is σ = 620916. Its totient is φ = 616704.

The previous prime is 618799. The next prime is 618823. The reversal of 618809 is 908816.

618809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 107584 + 511225 = 328^2 + 715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-618809 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 618809.

It is not an unprimeable number, because it can be changed into a prime (618859) 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, 524 + ... + 1229.

It is an arithmetic number, because the mean of its divisors is an integer number (155229).

2⁶¹⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

618809 is a deficient number, since it is larger than the sum of its proper divisors (2107).

618809 is a wasteful number, since it uses less digits than its factorization.

618809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2106.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 618809 is about 786.6441380955. The cubic root of 618809 is about 85.2155544056.

The spelling of 618809 in words is "six hundred eighteen thousand, eight hundred nine".