18858989 has 4 divisors (see below), whose sum is σ = 18867900. Its totient is φ = 18850080.

The previous prime is 18858971. The next prime is 18859013. The reversal of 18858989 is 98985881.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2778889 + 16080100 = 1667^2 + 4010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18858989 is a prime.

It is a super-2 number, since 2×18858989² = 711322932204242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18858929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 737 + ... + 6185.

It is an arithmetic number, because the mean of its divisors is an integer number (4716975).

Almost surely, 2^18858989 is an apocalyptic number.

It is an amenable number.

18858989 is a deficient number, since it is larger than the sum of its proper divisors (8911).

18858989 is an equidigital number, since it uses as much as digits as its factorization.

18858989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8910.

The product of its digits is 1658880, while the sum is 56.

The square root of 18858989 is about 4342.6937492759. The cubic root of 18858989 is about 266.1783952272.

The spelling of 18858989 in words is "eighteen million, eight hundred fifty-eight thousand, nine hundred eighty-nine".