18444158 has 4 divisors (see below), whose sum is σ = 27666240. Its totient is φ = 9222078.

The previous prime is 18444157. The next prime is 18444161. The reversal of 18444158 is 85144481.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85144481 = 431 ⋅197551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18444157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4611038 + ... + 4611041.

It is an arithmetic number, because the mean of its divisors is an integer number (6916560).

Almost surely, 2^18444158 is an apocalyptic number.

18444158 is a deficient number, since it is larger than the sum of its proper divisors (9222082).

18444158 is an equidigital number, since it uses as much as digits as its factorization.

18444158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9222081.

The product of its digits is 20480, while the sum is 35.

The square root of 18444158 is about 4294.6662268446. Note that the first 3 decimals coincide. The cubic root of 18444158 is about 264.2122470528.

The spelling of 18444158 in words is "eighteen million, four hundred forty-four thousand, one hundred fifty-eight".