18806243 has 4 divisors (see below), whose sum is σ = 19412928. Its totient is φ = 18199560.

The previous prime is 18806237. The next prime is 18806261. The reversal of 18806243 is 34260881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34260881 = 1877 ⋅18253.

It is a cyclic number.

It is not a de Polignac number, because 18806243 - 2²² = 14611939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18805243) 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, 303296 + ... + 303357.

It is an arithmetic number, because the mean of its divisors is an integer number (4853232).

Almost surely, 2^18806243 is an apocalyptic number.

18806243 is a deficient number, since it is larger than the sum of its proper divisors (606685).

18806243 is an equidigital number, since it uses as much as digits as its factorization.

18806243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606684.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 18806243 is about 4336.6165382704. The cubic root of 18806243 is about 265.9300087207.

The spelling of 18806243 in words is "eighteen million, eight hundred six thousand, two hundred forty-three".