18303013 has 4 divisors (see below), whose sum is σ = 18313740. Its totient is φ = 18292288.

The previous prime is 18303001. The next prime is 18303037. The reversal of 18303013 is 31030381.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 31030381 = 23 ⋅1349147.

It can be written as a sum of positive squares in 2 ways, for example, as 8773444 + 9529569 = 2962^2 + 3087^2 .

It is a cyclic number.

It is not a de Polignac number, because 18303013 - 2⁵ = 18302981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18303053) 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, 2170 + ... + 6427.

It is an arithmetic number, because the mean of its divisors is an integer number (4578435).

Almost surely, 2^18303013 is an apocalyptic number.

It is an amenable number.

18303013 is a deficient number, since it is larger than the sum of its proper divisors (10727).

18303013 is an equidigital number, since it uses as much as digits as its factorization.

18303013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10726.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 18303013 is about 4278.2020756388. The cubic root of 18303013 is about 263.5365539486.

Adding to 18303013 its reverse (31030381), we get a palindrome (49333394).

It can be divided in two parts, 18 and 303013, that added together give a triangular number (303031 = T₇₇₈).

The spelling of 18303013 in words is "eighteen million, three hundred three thousand, thirteen".