18000506 has 4 divisors (see below), whose sum is σ = 27000762. Its totient is φ = 9000252.

The previous prime is 18000473. The next prime is 18000527. The reversal of 18000506 is 60500081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60500081 = 233 ⋅259657.

It can be written as a sum of positive squares in only one way, i.e., 11162281 + 6838225 = 3341^2 + 2615^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4500125 + ... + 4500128.

Almost surely, 2^18000506 is an apocalyptic number.

18000506 is a deficient number, since it is larger than the sum of its proper divisors (9000256).

18000506 is an equidigital number, since it uses as much as digits as its factorization.

18000506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9000255.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 18000506 is about 4242.7003193721. The cubic root of 18000506 is about 262.0765951296.

Adding to 18000506 its reverse (60500081), we get a palindrome (78500587).

The spelling of 18000506 in words is "eighteen million, five hundred six", and thus it is an aban number.