18744442 has 4 divisors (see below), whose sum is σ = 28116666. Its totient is φ = 9372220.

The previous prime is 18744419. The next prime is 18744443. The reversal of 18744442 is 24444781.

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., 9678321 + 9066121 = 3111^2 + 3011^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18744398 and 18744407.

It is not an unprimeable number, because it can be changed into a prime (18744443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4686109 + ... + 4686112.

Almost surely, 2^18744442 is an apocalyptic number.

18744442 is a deficient number, since it is larger than the sum of its proper divisors (9372224).

18744442 is an equidigital number, since it uses as much as digits as its factorization.

18744442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9372223.

The product of its digits is 28672, while the sum is 34.

The square root of 18744442 is about 4329.4851887955. The cubic root of 18744442 is about 265.6383896734.

The spelling of 18744442 in words is "eighteen million, seven hundred forty-four thousand, four hundred forty-two".