18418513 has 4 divisors (see below), whose sum is σ = 18427888. Its totient is φ = 18409140.

The previous prime is 18418487. The next prime is 18418537. The reversal of 18418513 is 31581481.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 31581481 = 53 ⋅595877.

It is a cyclic number.

It is not a de Polignac number, because 18418513 - 2¹⁷ = 18287441 is a prime.

It is a super-2 number, since 2×18418513² = 678483242262338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18418573) 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, 483 + ... + 6088.

It is an arithmetic number, because the mean of its divisors is an integer number (4606972).

Almost surely, 2^18418513 is an apocalyptic number.

It is an amenable number.

18418513 is a deficient number, since it is larger than the sum of its proper divisors (9375).

18418513 is an equidigital number, since it uses as much as digits as its factorization.

18418513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9374.

The product of its digits is 3840, while the sum is 31.

The square root of 18418513 is about 4291.6795080714. The cubic root of 18418513 is about 264.0897355263.

Adding to 18418513 its reverse (31581481), we get a palindrome (49999994).

The spelling of 18418513 in words is "eighteen million, four hundred eighteen thousand, five hundred thirteen".