18120513 has 4 divisors (see below), whose sum is σ = 24160688. Its totient is φ = 12080340.

The previous prime is 18120503. The next prime is 18120517. The reversal of 18120513 is 31502181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18120513 - 2⁴ = 18120497 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18120513.

It is not an unprimeable number, because it can be changed into a prime (18120517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3020083 + ... + 3020088.

It is an arithmetic number, because the mean of its divisors is an integer number (6040172).

Almost surely, 2^18120513 is an apocalyptic number.

It is an amenable number.

18120513 is a deficient number, since it is larger than the sum of its proper divisors (6040175).

18120513 is an equidigital number, since it uses as much as digits as its factorization.

18120513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6040174.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 18120513 is about 4256.8195874385. The cubic root of 18120513 is about 262.6577156529.

Adding to 18120513 its reverse (31502181), we get a palindrome (49622694).

The spelling of 18120513 in words is "eighteen million, one hundred twenty thousand, five hundred thirteen".