18840643 has 8 divisors (see below), whose sum is σ = 19416416. Its totient is φ = 18273600.

The previous prime is 18840637. The next prime is 18840671. The reversal of 18840643 is 34604881.

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

It is a cyclic number.

It is not a de Polignac number, because 18840643 - 2²¹ = 16743491 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18840599 and 18840608.

It is not an unprimeable number, because it can be changed into a prime (18840623) 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, 2338 + ... + 6568.

It is an arithmetic number, because the mean of its divisors is an integer number (2427052).

Almost surely, 2^18840643 is an apocalyptic number.

18840643 is a deficient number, since it is larger than the sum of its proper divisors (575773).

18840643 is an equidigital number, since it uses as much as digits as its factorization.

18840643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4365.

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

The square root of 18840643 is about 4340.5809519003. The cubic root of 18840643 is about 266.0920545581.

The spelling of 18840643 in words is "eighteen million, eight hundred forty thousand, six hundred forty-three".