618909 has 4 divisors (see below), whose sum is σ = 825216. Its totient is φ = 412604.

The previous prime is 618883. The next prime is 618913. The reversal of 618909 is 909816.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 618909 - 2¹⁹ = 94621 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 618909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (618929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103149 + ... + 103154.

It is an arithmetic number, because the mean of its divisors is an integer number (206304).

2⁶¹⁸⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

618909 is a deficient number, since it is larger than the sum of its proper divisors (206307).

618909 is a wasteful number, since it uses less digits than its factorization.

618909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206306.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 618909 is about 786.7076966701. The cubic root of 618909 is about 85.2201444576.

It can be divided in two parts, 6 and 18909, that added together give a triangular number (18915 = T₁₉₄).

The spelling of 618909 in words is "six hundred eighteen thousand, nine hundred nine".