18040213 has 4 divisors (see below), whose sum is σ = 19101420. Its totient is φ = 16979008.

The previous prime is 18040207. The next prime is 18040229. The reversal of 18040213 is 31204081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31204081 = 3347 ⋅9323.

It can be written as a sum of positive squares in 2 ways, for example, as 16834609 + 1205604 = 4103^2 + 1098^2 .

It is a cyclic number.

It is not a de Polignac number, because 18040213 - 2⁵ = 18040181 is a prime.

It is a super-3 number, since 3×18040213³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18040273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530578 + ... + 530611.

It is an arithmetic number, because the mean of its divisors is an integer number (4775355).

Almost surely, 2^18040213 is an apocalyptic number.

It is an amenable number.

18040213 is a deficient number, since it is larger than the sum of its proper divisors (1061207).

18040213 is a wasteful number, since it uses less digits than its factorization.

18040213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061206.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 18040213 is about 4247.3771906907. The cubic root of 18040213 is about 262.2691569953.

Adding to 18040213 its reverse (31204081), we get a palindrome (49244294).

The spelling of 18040213 in words is "eighteen million, forty thousand, two hundred thirteen".