18859213 has 2 divisors, whose sum is σ = 18859214. Its totient is φ = 18859212.

The previous prime is 18859207. The next prime is 18859231. The reversal of 18859213 is 31295881.

Together with next prime (18859231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15976009 + 2883204 = 3997^2 + 1698^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18859213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18859013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9429606 + 9429607.

It is an arithmetic number, because the mean of its divisors is an integer number (9429607).

Almost surely, 2^18859213 is an apocalyptic number.

It is an amenable number.

18859213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18859213 is an equidigital number, since it uses as much as digits as its factorization.

18859213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 18859213 is about 4342.7195396433. The cubic root of 18859213 is about 266.1794490787.

The spelling of 18859213 in words is "eighteen million, eight hundred fifty-nine thousand, two hundred thirteen".