18039505 has 16 divisors (see below), whose sum is σ = 23701248. Its totient is φ = 13072000.

The previous prime is 18039503. The next prime is 18039529. The reversal of 18039505 is 50593081.

It is not a de Polignac number, because 18039505 - 2¹ = 18039503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18039503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23325 + ... + 24085.

It is an arithmetic number, because the mean of its divisors is an integer number (1481328).

Almost surely, 2^18039505 is an apocalyptic number.

It is an amenable number.

18039505 is a deficient number, since it is larger than the sum of its proper divisors (5661743).

18039505 is a wasteful number, since it uses less digits than its factorization.

18039505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 18039505 is about 4247.2938443202. The cubic root of 18039505 is about 262.2657259753.

The spelling of 18039505 in words is "eighteen million, thirty-nine thousand, five hundred five".