18684385 has 4 divisors (see below), whose sum is σ = 22421268. Its totient is φ = 14947504.

The previous prime is 18684373. The next prime is 18684389. The reversal of 18684385 is 58348681.

18684385 = 3056² + 3057².

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 9345249 + 9339136 = 3057^2 + 3056^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18684385 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18684389) 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, 1868434 + ... + 1868443.

It is an arithmetic number, because the mean of its divisors is an integer number (5605317).

Almost surely, 2^18684385 is an apocalyptic number.

18684385 is the 3057-th centered square number.

It is an amenable number.

18684385 is a deficient number, since it is larger than the sum of its proper divisors (3736883).

18684385 is an equidigital number, since it uses as much as digits as its factorization.

18684385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3736882.

The product of its digits is 184320, while the sum is 43.

The square root of 18684385 is about 4322.5438112297. The cubic root of 18684385 is about 265.3543852489.

The spelling of 18684385 in words is "eighteen million, six hundred eighty-four thousand, three hundred eighty-five".