18506987 has 2 divisors, whose sum is σ = 18506988. Its totient is φ = 18506986.

The previous prime is 18506981. The next prime is 18507011. The reversal of 18506987 is 78960581.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18506987 - 2²⁰ = 17458411 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18506981) 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, 9253493 + 9253494.

It is an arithmetic number, because the mean of its divisors is an integer number (9253494).

Almost surely, 2^18506987 is an apocalyptic number.

18506987 is a deficient number, since it is larger than the sum of its proper divisors (1).

18506987 is an equidigital number, since it uses as much as digits as its factorization.

18506987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 18506987 is about 4301.9747790985. The cubic root of 18506987 is about 264.5119151582.

The spelling of 18506987 in words is "eighteen million, five hundred six thousand, nine hundred eighty-seven".