18218593 has 2 divisors, whose sum is σ = 18218594. Its totient is φ = 18218592.

The previous prime is 18218561. The next prime is 18218597. The reversal of 18218593 is 39581281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17918289 + 300304 = 4233^2 + 548^2 .

It is a cyclic number.

It is not a de Polignac number, because 18218593 - 2⁵ = 18218561 is a prime.

It is not a weakly prime, because it can be changed into another prime (18218597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9109296 + 9109297.

It is an arithmetic number, because the mean of its divisors is an integer number (9109297).

Almost surely, 2^18218593 is an apocalyptic number.

It is an amenable number.

18218593 is a deficient number, since it is larger than the sum of its proper divisors (1).

18218593 is an equidigital number, since it uses as much as digits as its factorization.

18218593 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 18218593 is about 4268.3243784886. The cubic root of 18218593 is about 263.1307546656.

The spelling of 18218593 in words is "eighteen million, two hundred eighteen thousand, five hundred ninety-three".