18138073 has 4 divisors (see below), whose sum is σ = 18356688. Its totient is φ = 17919460.

The previous prime is 18138067. The next prime is 18138077. The reversal of 18138073 is 37083181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 37083181 = 61 ⋅607921.

It is a cyclic number.

It is not a de Polignac number, because 18138073 - 2⁵ = 18138041 is a prime.

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 a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18138077) 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, 109183 + ... + 109348.

It is an arithmetic number, because the mean of its divisors is an integer number (4589172).

Almost surely, 2^18138073 is an apocalyptic number.

It is an amenable number.

18138073 is a deficient number, since it is larger than the sum of its proper divisors (218615).

18138073 is an equidigital number, since it uses as much as digits as its factorization.

18138073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218614.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 18138073 is about 4258.8816607180. The cubic root of 18138073 is about 262.7425326118.

The spelling of 18138073 in words is "eighteen million, one hundred thirty-eight thousand, seventy-three".