18072013 has 4 divisors (see below), whose sum is σ = 18090108. Its totient is φ = 18053920.

The previous prime is 18072011. The next prime is 18072023. The reversal of 18072013 is 31027081.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7851204 + 10220809 = 2802^2 + 3197^2 .

It is a cyclic number.

It is not a de Polignac number, because 18072013 - 2¹ = 18072011 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18072011) 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, 7456 + ... + 9577.

It is an arithmetic number, because the mean of its divisors is an integer number (4522527).

Almost surely, 2^18072013 is an apocalyptic number.

It is an amenable number.

18072013 is a deficient number, since it is larger than the sum of its proper divisors (18095).

18072013 is a wasteful number, since it uses less digits than its factorization.

18072013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18094.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 18072013 is about 4251.1190291499. The cubic root of 18072013 is about 262.4231696540.

Adding to 18072013 its reverse (31027081), we get a palindrome (49099094).

The spelling of 18072013 in words is "eighteen million, seventy-two thousand, thirteen".