18005285 has 12 divisors (see below), whose sum is σ = 21921228. Its totient is φ = 14197248.

The previous prime is 18005279. The next prime is 18005287. The reversal of 18005285 is 58250081.

It can be written as a sum of positive squares in 2 ways, for example, as 13786369 + 4218916 = 3713^2 + 2054^2 .

It is not a de Polignac number, because 18005285 - 2⁴ = 18005269 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18005287) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30917 + ... + 31493.

It is an arithmetic number, because the mean of its divisors is an integer number (1826769).

Almost surely, 2^18005285 is an apocalyptic number.

It is an amenable number.

18005285 is a deficient number, since it is larger than the sum of its proper divisors (3915943).

18005285 is an frugal number, since it uses more digits than its factorization.

18005285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 29.

The square root of 18005285 is about 4243.2634846307. The cubic root of 18005285 is about 262.0997862041.

The spelling of 18005285 in words is "eighteen million, five thousand, two hundred eighty-five".