18180513 has 18 divisors (see below), whose sum is σ = 28438566. Its totient is φ = 11187072.

The previous prime is 18180509. The next prime is 18180523. The reversal of 18180513 is 31508181.

It can be written as a sum of positive squares in 3 ways, for example, as 1016064 + 17164449 = 1008^2 + 4143^2 .

It is not a de Polignac number, because 18180513 - 2² = 18180509 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18180523) 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 17 ways as a sum of consecutive naturals, for example, 4456 + ... + 7497.

Almost surely, 2^18180513 is an apocalyptic number.

18180513 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18180513 is a deficient number, since it is larger than the sum of its proper divisors (10258053).

18180513 is a wasteful number, since it uses less digits than its factorization.

18180513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11985 (or 11969 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 18180513 is about 4263.8612782313. The cubic root of 18180513 is about 262.9472972412.

Adding to 18180513 its reverse (31508181), we get a palindrome (49688694).

The spelling of 18180513 in words is "eighteen million, one hundred eighty thousand, five hundred thirteen".