18520213 has 2 divisors, whose sum is σ = 18520214. Its totient is φ = 18520212.

The previous prime is 18520199. The next prime is 18520217. The reversal of 18520213 is 31202581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12404484 + 6115729 = 3522^2 + 2473^2 .

It is a cyclic number.

It is not a de Polignac number, because 18520213 - 2⁵ = 18520181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18520217) 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 as a sum of consecutive naturals, namely, 9260106 + 9260107.

It is an arithmetic number, because the mean of its divisors is an integer number (9260107).

Almost surely, 2^18520213 is an apocalyptic number.

It is an amenable number.

18520213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18520213 is an equidigital number, since it uses as much as digits as its factorization.

18520213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 18520213 is about 4303.5117055726. The cubic root of 18520213 is about 264.5749112136.

Adding to 18520213 its reverse (31202581), we get a palindrome (49722794).

The spelling of 18520213 in words is "eighteen million, five hundred twenty thousand, two hundred thirteen".