18356213 has 2 divisors, whose sum is σ = 18356214. Its totient is φ = 18356212.

The previous prime is 18356207. The next prime is 18356281. The reversal of 18356213 is 31265381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13235044 + 5121169 = 3638^2 + 2263^2 .

It is a cyclic number.

It is not a de Polignac number, because 18356213 - 2¹⁴ = 18339829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18359213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9178106 + 9178107.

It is an arithmetic number, because the mean of its divisors is an integer number (9178107).

Almost surely, 2^18356213 is an apocalyptic number.

It is an amenable number.

18356213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18356213 is an equidigital number, since it uses as much as digits as its factorization.

18356213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

The square root of 18356213 is about 4284.4151292796. The cubic root of 18356213 is about 263.7916409625.

The spelling of 18356213 in words is "eighteen million, three hundred fifty-six thousand, two hundred thirteen".