18918681842 has 4 divisors (see below), whose sum is σ = 28378022766. Its totient is φ = 9459340920.

The previous prime is 18918681839. The next prime is 18918681853. The reversal of 18918681842 is 24818681981.

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., 18338305561 + 580376281 = 135419^2 + 24091^2 .

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, 4729670459 + ... + 4729670462.

Almost surely, 2^18918681842 is an apocalyptic number.

18918681842 is a deficient number, since it is larger than the sum of its proper divisors (9459340924).

18918681842 is an equidigital number, since it uses as much as digits as its factorization.

18918681842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9459340923.

The product of its digits is 1769472, while the sum is 56.

The spelling of 18918681842 in words is "eighteen billion, nine hundred eighteen million, six hundred eighty-one thousand, eight hundred forty-two".