18398789 has 4 divisors (see below), whose sum is σ = 19033260. Its totient is φ = 17764320.

The previous prime is 18398767. The next prime is 18398813. The reversal of 18398789 is 98789381.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11937025 + 6461764 = 3455^2 + 2542^2 .

It is a cyclic number.

It is not a de Polignac number, because 18398789 - 2¹² = 18394693 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18398789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18398719) 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, 317192 + ... + 317249.

It is an arithmetic number, because the mean of its divisors is an integer number (4758315).

Almost surely, 2^18398789 is an apocalyptic number.

It is an amenable number.

18398789 is a deficient number, since it is larger than the sum of its proper divisors (634471).

18398789 is an equidigital number, since it uses as much as digits as its factorization.

18398789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634470.

The product of its digits is 870912, while the sum is 53.

The square root of 18398789 is about 4289.3809576674. The cubic root of 18398789 is about 263.9954324661.

The spelling of 18398789 in words is "eighteen million, three hundred ninety-eight thousand, seven hundred eighty-nine".