18119989 has 4 divisors (see below), whose sum is σ = 18417100. Its totient is φ = 17822880.

The previous prime is 18119971. The next prime is 18120007. The reversal of 18119989 is 98991181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98991181 = 29 ⋅3413489.

It is an interprime number because it is at equal distance from previous prime (18119971) and next prime (18120007).

It can be written as a sum of positive squares in 2 ways, for example, as 4169764 + 13950225 = 2042^2 + 3735^2 .

It is a cyclic number.

It is not a de Polignac number, because 18119989 - 2²¹ = 16022837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18119489) 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 in 3 ways as a sum of consecutive naturals, for example, 148464 + ... + 148585.

It is an arithmetic number, because the mean of its divisors is an integer number (4604275).

Almost surely, 2^18119989 is an apocalyptic number.

It is an amenable number.

18119989 is a deficient number, since it is larger than the sum of its proper divisors (297111).

18119989 is an equidigital number, since it uses as much as digits as its factorization.

18119989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297110.

The product of its digits is 46656, while the sum is 46.

The square root of 18119989 is about 4256.7580386956. The cubic root of 18119989 is about 262.6551838267.

The spelling of 18119989 in words is "eighteen million, one hundred nineteen thousand, nine hundred eighty-nine".