18990586 has 4 divisors (see below), whose sum is σ = 28485882. Its totient is φ = 9495292.

The previous prime is 18990541. The next prime is 18990599. The reversal of 18990586 is 68509981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68509981 = 191 ⋅358691.

It can be written as a sum of positive squares in only one way, i.e., 11323225 + 7667361 = 3365^2 + 2769^2 .

It is an unprimeable number.

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, 4747645 + ... + 4747648.

Almost surely, 2^18990586 is an apocalyptic number.

18990586 is a deficient number, since it is larger than the sum of its proper divisors (9495296).

18990586 is an equidigital number, since it uses as much as digits as its factorization.

18990586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9495295.

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 18990586 is about 4357.8189498877. The cubic root of 18990586 is about 266.7960868317.

The spelling of 18990586 in words is "eighteen million, nine hundred ninety thousand, five hundred eighty-six".