18678689 has 4 divisors (see below), whose sum is σ = 18688020. Its totient is φ = 18669360.

The previous prime is 18678683. The next prime is 18678701. The reversal of 18678689 is 98687681.

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 11022400 + 7656289 = 3320^2 + 2767^2 .

It is a cyclic number.

It is not a de Polignac number, because 18678689 - 2⁸ = 18678433 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 18678689.

It is not an unprimeable number, because it can be changed into a prime (18678683) 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, 302 + ... + 6119.

It is an arithmetic number, because the mean of its divisors is an integer number (4672005).

Almost surely, 2^18678689 is an apocalyptic number.

It is an amenable number.

18678689 is a deficient number, since it is larger than the sum of its proper divisors (9331).

18678689 is an equidigital number, since it uses as much as digits as its factorization.

18678689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9330.

The product of its digits is 1161216, while the sum is 53.

The square root of 18678689 is about 4321.8848897212. The cubic root of 18678689 is about 265.3274177714.

The spelling of 18678689 in words is "eighteen million, six hundred seventy-eight thousand, six hundred eighty-nine".