1998000000 has 448 divisors, whose sum is σ = 7570215600. Its totient is φ = 518400000.

The previous prime is 1997999977. The next prime is 1998000029. The reversal of 1998000000 is 8991.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 53999982 + ... + 54000018.

Almost surely, 2^1998000000 is an apocalyptic number.

1998000000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1998000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3785107800).

1998000000 is an abundant number, since it is smaller than the sum of its proper divisors (5572215600).

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

1998000000 is an frugal number, since it uses more digits than its factorization.

1998000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 1998000000 is about 44698.9932772540. The cubic root of 1998000000 is about 1259.5009361425.

Adding to 1998000000 its reverse (8991), we get a palindrome (1998008991).

The spelling of 1998000000 in words is "one billion, nine hundred ninety-eight million", and thus it is an aban number.