18230138 has 4 divisors (see below), whose sum is σ = 27345210. Its totient is φ = 9115068.

The previous prime is 18230131. The next prime is 18230161. The reversal of 18230138 is 83103281.

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., 18088009 + 142129 = 4253^2 + 377^2 .

It is not an unprimeable number, because it can be changed into a prime (18230131) by changing a digit.

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, 4557533 + ... + 4557536.

Almost surely, 2^18230138 is an apocalyptic number.

18230138 is a deficient number, since it is larger than the sum of its proper divisors (9115072).

18230138 is an equidigital number, since it uses as much as digits as its factorization.

18230138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9115071.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 18230138 is about 4269.6765685471. The cubic root of 18230138 is about 263.1863243265.

The spelling of 18230138 in words is "eighteen million, two hundred thirty thousand, one hundred thirty-eight".