18985887818 has 4 divisors (see below), whose sum is σ = 28478831730. Its totient is φ = 9492943908.

The previous prime is 18985887799. The next prime is 18985887829. The reversal of 18985887818 is 81878858981.

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., 11790267889 + 7195619929 = 108583^2 + 84827^2 .

It is a super-2 number, since 2×18985887818² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4746471953 + ... + 4746471956.

Almost surely, 2^18985887818 is an apocalyptic number.

18985887818 is a deficient number, since it is larger than the sum of its proper divisors (9492943912).

18985887818 is an equidigital number, since it uses as much as digits as its factorization.

18985887818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9492943911.

The product of its digits is 82575360, while the sum is 71.

The spelling of 18985887818 in words is "eighteen billion, nine hundred eighty-five million, eight hundred eighty-seven thousand, eight hundred eighteen".