18868393 has 2 divisors, whose sum is σ = 18868394. Its totient is φ = 18868392.

The previous prime is 18868379. The next prime is 18868411. The reversal of 18868393 is 39386881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14653584 + 4214809 = 3828^2 + 2053^2 .

It is an emirp because it is prime and its reverse (39386881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18868393 - 2⁵ = 18868361 is a prime.

It is not a weakly prime, because it can be changed into another prime (18868373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9434196 + 9434197.

It is an arithmetic number, because the mean of its divisors is an integer number (9434197).

Almost surely, 2^18868393 is an apocalyptic number.

It is an amenable number.

18868393 is a deficient number, since it is larger than the sum of its proper divisors (1).

18868393 is an equidigital number, since it uses as much as digits as its factorization.

18868393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 18868393 is about 4343.7763524380. The cubic root of 18868393 is about 266.2226309969. Note that the first 3 decimals are identical.

The spelling of 18868393 in words is "eighteen million, eight hundred sixty-eight thousand, three hundred ninety-three".