18213443 has 4 divisors (see below), whose sum is σ = 19284840. Its totient is φ = 17142048.

The previous prime is 18213383. The next prime is 18213449. The reversal of 18213443 is 34431281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34431281 = 79 ⋅435839.

It is a cyclic number.

It is not a de Polignac number, because 18213443 - 2⁶ = 18213379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18213449) 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, 535673 + ... + 535706.

It is an arithmetic number, because the mean of its divisors is an integer number (4821210).

Almost surely, 2^18213443 is an apocalyptic number.

18213443 is a deficient number, since it is larger than the sum of its proper divisors (1071397).

18213443 is a wasteful number, since it uses less digits than its factorization.

18213443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071396.

The product of its digits is 2304, while the sum is 26.

The square root of 18213443 is about 4267.7210546145. The cubic root of 18213443 is about 263.1059585486.

The spelling of 18213443 in words is "eighteen million, two hundred thirteen thousand, four hundred forty-three".