18243139 has 2 divisors, whose sum is σ = 18243140. Its totient is φ = 18243138.

The previous prime is 18243133. The next prime is 18243149. The reversal of 18243139 is 93134281.

It is a weak prime.

It is an emirp because it is prime and its reverse (93134281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18243139 - 2¹³ = 18234947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18243139.

It is not a weakly prime, because it can be changed into another prime (18243133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9121569 + 9121570.

It is an arithmetic number, because the mean of its divisors is an integer number (9121570).

Almost surely, 2^18243139 is an apocalyptic number.

18243139 is a deficient number, since it is larger than the sum of its proper divisors (1).

18243139 is an equidigital number, since it uses as much as digits as its factorization.

18243139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 31.

The square root of 18243139 is about 4271.1987778608. The cubic root of 18243139 is about 263.2488740874.

The spelling of 18243139 in words is "eighteen million, two hundred forty-three thousand, one hundred thirty-nine".