18256213 has 2 divisors, whose sum is σ = 18256214. Its totient is φ = 18256212.

The previous prime is 18256211. The next prime is 18256219. The reversal of 18256213 is 31265281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11819844 + 6436369 = 3438^2 + 2537^2 .

It is an emirp because it is prime and its reverse (31265281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18256213 - 2¹ = 18256211 is a prime.

Together with 18256211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18256211) 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, 9128106 + 9128107.

It is an arithmetic number, because the mean of its divisors is an integer number (9128107).

Almost surely, 2^18256213 is an apocalyptic number.

It is an amenable number.

18256213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18256213 is an equidigital number, since it uses as much as digits as its factorization.

18256213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 28.

The square root of 18256213 is about 4272.7289874271. The cubic root of 18256213 is about 263.3117451013.

The spelling of 18256213 in words is "eighteen million, two hundred fifty-six thousand, two hundred thirteen".