18043393 has 2 divisors, whose sum is σ = 18043394. Its totient is φ = 18043392.

The previous prime is 18043391. The next prime is 18043469. The reversal of 18043393 is 39334081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12623809 + 5419584 = 3553^2 + 2328^2 .

It is a cyclic number.

It is not a de Polignac number, because 18043393 - 2¹ = 18043391 is a prime.

Together with 18043391, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18043391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9021696 + 9021697.

It is an arithmetic number, because the mean of its divisors is an integer number (9021697).

Almost surely, 2^18043393 is an apocalyptic number.

It is an amenable number.

18043393 is a deficient number, since it is larger than the sum of its proper divisors (1).

18043393 is an equidigital number, since it uses as much as digits as its factorization.

18043393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 18043393 is about 4247.7515228648. The cubic root of 18043393 is about 262.2845664016.

The spelling of 18043393 in words is "eighteen million, forty-three thousand, three hundred ninety-three".