18128939 has 2 divisors, whose sum is σ = 18128940. Its totient is φ = 18128938.

The previous prime is 18128933. The next prime is 18128951. The reversal of 18128939 is 93982181.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18128939 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18128896 and 18128905.

It is not a weakly prime, because it can be changed into another prime (18128933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9064469 + 9064470.

It is an arithmetic number, because the mean of its divisors is an integer number (9064470).

Almost surely, 2^18128939 is an apocalyptic number.

18128939 is a deficient number, since it is larger than the sum of its proper divisors (1).

18128939 is an equidigital number, since it uses as much as digits as its factorization.

18128939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 41.

The square root of 18128939 is about 4257.8091784391. The cubic root of 18128939 is about 262.6984211039.

The spelling of 18128939 in words is "eighteen million, one hundred twenty-eight thousand, nine hundred thirty-nine".