18738943 has 2 divisors, whose sum is σ = 18738944. Its totient is φ = 18738942.

The previous prime is 18738919. The next prime is 18738961. The reversal of 18738943 is 34983781.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18738943 - 2²¹ = 16641791 is a prime.

It is a super-2 number, since 2×18738943² = 702295969514498, which contains 22 as substring.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 18738943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18732943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9369471 + 9369472.

It is an arithmetic number, because the mean of its divisors is an integer number (9369472).

Almost surely, 2^18738943 is an apocalyptic number.

18738943 is a deficient number, since it is larger than the sum of its proper divisors (1).

18738943 is an equidigital number, since it uses as much as digits as its factorization.

18738943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 43.

The square root of 18738943 is about 4328.8500782540. The cubic root of 18738943 is about 265.6124106236.

It can be divided in two parts, 1873 and 8943, that added together give a square (10816 = 104²).

The spelling of 18738943 in words is "eighteen million, seven hundred thirty-eight thousand, nine hundred forty-three".