18321939 has 12 divisors (see below), whose sum is σ = 27378000. Its totient is φ = 11793264.

The previous prime is 18321929. The next prime is 18321967. The reversal of 18321939 is 93912381.

It is not a de Polignac number, because 18321939 - 2⁴ = 18321923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18321929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34839 + ... + 35360.

It is an arithmetic number, because the mean of its divisors is an integer number (2281500).

Almost surely, 2^18321939 is an apocalyptic number.

18321939 is a deficient number, since it is larger than the sum of its proper divisors (9056061).

18321939 is a wasteful number, since it uses less digits than its factorization.

18321939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70234 (or 70231 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 18321939 is about 4280.4134146131. The cubic root of 18321939 is about 263.6273582086.

It can be divided in two parts, 183 and 21939, that added together give a palindrome (22122).

The spelling of 18321939 in words is "eighteen million, three hundred twenty-one thousand, nine hundred thirty-nine".