18986984 has 8 divisors (see below), whose sum is σ = 35600610. Its totient is φ = 9493488.

The previous prime is 18986971. The next prime is 18986987. The reversal of 18986984 is 48968981.

It can be written as a sum of positive squares in only one way, i.e., 14668900 + 4318084 = 3830^2 + 2078^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×18986984² = 721011122832512, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18986987) 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, 1186679 + ... + 1186694.

Almost surely, 2^18986984 is an apocalyptic number.

It is an amenable number.

18986984 is a deficient number, since it is larger than the sum of its proper divisors (16613626).

18986984 is a wasteful number, since it uses less digits than its factorization.

18986984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2373379 (or 2373375 counting only the distinct ones).

The product of its digits is 995328, while the sum is 53.

The square root of 18986984 is about 4357.4056501547. The cubic root of 18986984 is about 266.7792177670.

The spelling of 18986984 in words is "eighteen million, nine hundred eighty-six thousand, nine hundred eighty-four".