18724243 has 2 divisors, whose sum is σ = 18724244. Its totient is φ = 18724242.

The previous prime is 18724241. The next prime is 18724247. The reversal of 18724243 is 34242781.

It is a weak prime.

It is an emirp because it is prime and its reverse (34242781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18724243 - 2¹ = 18724241 is a prime.

Together with 18724241, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18724241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9362121 + 9362122.

It is an arithmetic number, because the mean of its divisors is an integer number (9362122).

Almost surely, 2^18724243 is an apocalyptic number.

18724243 is a deficient number, since it is larger than the sum of its proper divisors (1).

18724243 is an equidigital number, since it uses as much as digits as its factorization.

18724243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 31.

The square root of 18724243 is about 4327.1518346367. The cubic root of 18724243 is about 265.5429381199.

The spelling of 18724243 in words is "eighteen million, seven hundred twenty-four thousand, two hundred forty-three".