18066481 has 4 divisors (see below), whose sum is σ = 18407412. Its totient is φ = 17725552.

The previous prime is 18066479. The next prime is 18066487. The reversal of 18066481 is 18466081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18466081 = 19 ⋅971899.

It can be written as a sum of positive squares in 2 ways, for example, as 8946081 + 9120400 = 2991^2 + 3020^2 .

It is a cyclic number.

It is not a de Polignac number, because 18066481 - 2¹ = 18066479 is a prime.

It is a super-2 number, since 2×18066481² = 652795471446722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18066487) 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 3 ways as a sum of consecutive naturals, for example, 170386 + ... + 170491.

It is an arithmetic number, because the mean of its divisors is an integer number (4601853).

Almost surely, 2^18066481 is an apocalyptic number.

It is an amenable number.

18066481 is a deficient number, since it is larger than the sum of its proper divisors (340931).

18066481 is an equidigital number, since it uses as much as digits as its factorization.

18066481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340930.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 18066481 is about 4250.4683271376. The cubic root of 18066481 is about 262.3963902516.

The spelling of 18066481 in words is "eighteen million, sixty-six thousand, four hundred eighty-one".