18079909 has 16 divisors (see below), whose sum is σ = 19603584. Its totient is φ = 16632000.

The previous prime is 18079907. The next prime is 18079931. The reversal of 18079909 is 90997081.

It is a cyclic number.

It is not a de Polignac number, because 18079909 - 2¹ = 18079907 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18079903) 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 15 ways as a sum of consecutive naturals, for example, 99799 + ... + 99979.

It is an arithmetic number, because the mean of its divisors is an integer number (1225224).

Almost surely, 2^18079909 is an apocalyptic number.

It is an amenable number.

18079909 is a deficient number, since it is larger than the sum of its proper divisors (1523675).

18079909 is a wasteful number, since it uses less digits than its factorization.

18079909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 18079909 is about 4252.0476243805. The cubic root of 18079909 is about 262.4613832838.

It can be divided in two parts, 180 and 79909, that added together give a square (80089 = 283²).

The spelling of 18079909 in words is "eighteen million, seventy-nine thousand, nine hundred nine".