18039443 has 2 divisors, whose sum is σ = 18039444. Its totient is φ = 18039442.

The previous prime is 18039419. The next prime is 18039449. The reversal of 18039443 is 34493081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18039443 - 2¹⁸ = 17777299 is a prime.

It is not a weakly prime, because it can be changed into another prime (18039449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9019721 + 9019722.

It is an arithmetic number, because the mean of its divisors is an integer number (9019722).

Almost surely, 2^18039443 is an apocalyptic number.

18039443 is a deficient number, since it is larger than the sum of its proper divisors (1).

18039443 is an equidigital number, since it uses as much as digits as its factorization.

18039443 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 18039443 is about 4247.2865455488. The cubic root of 18039443 is about 262.2654255145.

The spelling of 18039443 in words is "eighteen million, thirty-nine thousand, four hundred forty-three".