18789986 has 4 divisors (see below), whose sum is σ = 28184982. Its totient is φ = 9394992.

The previous prime is 18789983. The next prime is 18790001. The reversal of 18789986 is 68998781.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17799961 + 990025 = 4219^2 + 995^2 .

It is not an unprimeable number, because it can be changed into a prime (18789983) 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, 4697495 + ... + 4697498.

Almost surely, 2^18789986 is an apocalyptic number.

18789986 is a deficient number, since it is larger than the sum of its proper divisors (9394996).

18789986 is an equidigital number, since it uses as much as digits as its factorization.

18789986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9394995.

The product of its digits is 1741824, while the sum is 56.

The square root of 18789986 is about 4334.7417454792. The cubic root of 18789986 is about 265.8533591655.

The spelling of 18789986 in words is "eighteen million, seven hundred eighty-nine thousand, nine hundred eighty-six".