18408643 has 4 divisors (see below), whose sum is σ = 20082168. Its totient is φ = 16735120.

The previous prime is 18408617. The next prime is 18408661. The reversal of 18408643 is 34680481.

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

It is a cyclic number.

It is not a de Polignac number, because 18408643 - 2¹³ = 18400451 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18408599 and 18408608.

It is not an unprimeable number, because it can be changed into a prime (18408613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 836746 + ... + 836767.

It is an arithmetic number, because the mean of its divisors is an integer number (5020542).

Almost surely, 2^18408643 is an apocalyptic number.

18408643 is a deficient number, since it is larger than the sum of its proper divisors (1673525).

18408643 is a wasteful number, since it uses less digits than its factorization.

18408643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673524.

The product of its (nonzero) digits is 18432, while the sum is 34.

The square root of 18408643 is about 4290.5294545079. The cubic root of 18408643 is about 264.0425541673.

The spelling of 18408643 in words is "eighteen million, four hundred eight thousand, six hundred forty-three".