18543442 has 4 divisors (see below), whose sum is σ = 27815166. Its totient is φ = 9271720.

The previous prime is 18543419. The next prime is 18543457. The reversal of 18543442 is 24434581.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11621281 + 6922161 = 3409^2 + 2631^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 4635859 + ... + 4635862.

Almost surely, 2^18543442 is an apocalyptic number.

18543442 is a deficient number, since it is larger than the sum of its proper divisors (9271724).

18543442 is an equidigital number, since it uses as much as digits as its factorization.

18543442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9271723.

The product of its digits is 15360, while the sum is 31.

The square root of 18543442 is about 4306.2097022788. The cubic root of 18543442 is about 264.6854794693.

The spelling of 18543442 in words is "eighteen million, five hundred forty-three thousand, four hundred forty-two".