18133987 has 2 divisors, whose sum is σ = 18133988. Its totient is φ = 18133986.

The previous prime is 18133967. The next prime is 18133991. The reversal of 18133987 is 78933181.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18133987 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18133957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9066993 + 9066994.

It is an arithmetic number, because the mean of its divisors is an integer number (9066994).

Almost surely, 2^18133987 is an apocalyptic number.

18133987 is a deficient number, since it is larger than the sum of its proper divisors (1).

18133987 is an equidigital number, since it uses as much as digits as its factorization.

18133987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 40.

The square root of 18133987 is about 4258.4019303020. The cubic root of 18133987 is about 262.7228016181.

The spelling of 18133987 in words is "eighteen million, one hundred thirty-three thousand, nine hundred eighty-seven".