18071138 has 4 divisors (see below), whose sum is σ = 27106710. Its totient is φ = 9035568.

The previous prime is 18071113. The next prime is 18071143. The reversal of 18071138 is 83117081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83117081 = 1741 ⋅47741.

It can be written as a sum of positive squares in only one way, i.e., 12794929 + 5276209 = 3577^2 + 2297^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18071138.

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, 4517783 + ... + 4517786.

Almost surely, 2^18071138 is an apocalyptic number.

18071138 is a deficient number, since it is larger than the sum of its proper divisors (9035572).

18071138 is an equidigital number, since it uses as much as digits as its factorization.

18071138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9035571.

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 18071138 is about 4251.0161138250. The cubic root of 18071138 is about 262.4189343026.

The spelling of 18071138 in words is "eighteen million, seventy-one thousand, one hundred thirty-eight".