18381234658 has 4 divisors (see below), whose sum is σ = 27571851990. Its totient is φ = 9190617328.

The previous prime is 18381234631. The next prime is 18381234673. The reversal of 18381234658 is 85643218381.

It is a happy number.

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., 17764358089 + 616876569 = 133283^2 + 24837^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4595308663 + ... + 4595308666.

Almost surely, 2^18381234658 is an apocalyptic number.

18381234658 is a deficient number, since it is larger than the sum of its proper divisors (9190617332).

18381234658 is an equidigital number, since it uses as much as digits as its factorization.

18381234658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9190617331.

The product of its digits is 1105920, while the sum is 49.

The spelling of 18381234658 in words is "eighteen billion, three hundred eighty-one million, two hundred thirty-four thousand, six hundred fifty-eight".