1998198181836 has 30 divisors (see below), whose sum is σ = 5223684753980. Its totient is φ = 666066060504.

The previous prime is 1998198181829. The next prime is 1998198181843. The reversal of 1998198181836 is 6381818918991.

It is an interprime number because it is at equal distance from previous prime (1998198181829) and next prime (1998198181843).

It is a super-2 number, since 2×1998198181836² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3083638846 + ... + 3083639493.

Almost surely, 2^{1998198181836} is an apocalyptic number.

It is an amenable number.

1998198181836 is an abundant number, since it is smaller than the sum of its proper divisors (3225486572144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1998198181836 is a wasteful number, since it uses less digits than its factorization.

1998198181836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6167278355 (or 6167278344 counting only the distinct ones).

The product of its digits is 53747712, while the sum is 72.

The spelling of 1998198181836 in words is "one trillion, nine hundred ninety-eight billion, one hundred ninety-eight million, one hundred eighty-one thousand, eight hundred thirty-six".