18039605 has 4 divisors (see below), whose sum is σ = 21647532. Its totient is φ = 14431680.

The previous prime is 18039599. The next prime is 18039629. The reversal of 18039605 is 50693081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50693081 = 23 ⋅2204047.

It can be written as a sum of positive squares in 2 ways, for example, as 5373124 + 12666481 = 2318^2 + 3559^2 .

It is not a de Polignac number, because 18039605 - 2⁴ = 18039589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 1803956 + ... + 1803965.

It is an arithmetic number, because the mean of its divisors is an integer number (5411883).

Almost surely, 2^18039605 is an apocalyptic number.

It is an amenable number.

18039605 is a deficient number, since it is larger than the sum of its proper divisors (3607927).

18039605 is an equidigital number, since it uses as much as digits as its factorization.

18039605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3607926.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 18039605 is about 4247.3056165056. The cubic root of 18039605 is about 262.2662105881.

It can be divided in two parts, 180 and 39605, that multiplied together give a square (7128900 = 2670²).

The spelling of 18039605 in words is "eighteen million, thirty-nine thousand, six hundred five".