18013513 has 4 divisors (see below), whose sum is σ = 20586880. Its totient is φ = 15440148.

The previous prime is 18013507. The next prime is 18013529. The reversal of 18013513 is 31531081.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18013513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18013213) 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, 1286673 + ... + 1286686.

It is an arithmetic number, because the mean of its divisors is an integer number (5146720).

Almost surely, 2^18013513 is an apocalyptic number.

It is an amenable number.

18013513 is a deficient number, since it is larger than the sum of its proper divisors (2573367).

18013513 is an equidigital number, since it uses as much as digits as its factorization.

18013513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2573366.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 18013513 is about 4244.2329106683. The cubic root of 18013513 is about 262.1397046433.

Adding to 18013513 its reverse (31531081), we get a palindrome (49544594).

The spelling of 18013513 in words is "eighteen million, thirteen thousand, five hundred thirteen".