18406243 has 4 divisors (see below), whose sum is σ = 18415368. Its totient is φ = 18397120.

The previous prime is 18406229. The next prime is 18406319. The reversal of 18406243 is 34260481.

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, and also an emirpimes, since its reverse is a distinct semiprime: 34260481 = 163 ⋅210187.

It is a cyclic number.

It is not a de Polignac number, because 18406243 - 2⁹ = 18405731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18406043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46 + ... + 6067.

It is an arithmetic number, because the mean of its divisors is an integer number (4603842).

Almost surely, 2^18406243 is an apocalyptic number.

18406243 is a deficient number, since it is larger than the sum of its proper divisors (9125).

18406243 is an equidigital number, since it uses as much as digits as its factorization.

18406243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9124.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 18406243 is about 4290.2497596294. The cubic root of 18406243 is about 264.0310789475.

The spelling of 18406243 in words is "eighteen million, four hundred six thousand, two hundred forty-three".