18398643 has 8 divisors (see below), whose sum is σ = 25598208. Its totient is φ = 11732424.

The previous prime is 18398609. The next prime is 18398647. The reversal of 18398643 is 34689381.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18398643 - 2¹⁰ = 18397619 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18398595 and 18398604.

It is not an unprimeable number, because it can be changed into a prime (18398647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133255 + ... + 133392.

It is an arithmetic number, because the mean of its divisors is an integer number (3199776).

Almost surely, 2^18398643 is an apocalyptic number.

18398643 is a deficient number, since it is larger than the sum of its proper divisors (7199565).

18398643 is a wasteful number, since it uses less digits than its factorization.

18398643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266673.

The product of its digits is 124416, while the sum is 42.

The square root of 18398643 is about 4289.3639388609. The cubic root of 18398643 is about 263.9947341695.

The spelling of 18398643 in words is "eighteen million, three hundred ninety-eight thousand, six hundred forty-three".