1998939558 has 32 divisors (see below), whose sum is σ = 4984369920. Its totient is φ = 519204960.

The previous prime is 1998939557. The next prime is 1998939583. The reversal of 1998939558 is 8559398991.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998939557) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 2162893 + ... + 2163816.

It is an arithmetic number, because the mean of its divisors is an integer number (155761560).

Almost surely, 2^1998939558 is an apocalyptic number.

1998939558 is an abundant number, since it is smaller than the sum of its proper divisors (2985430362).

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

1998939558 is a wasteful number, since it uses less digits than its factorization.

1998939558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4326732.

The product of its digits is 31492800, while the sum is 66.

The square root of 1998939558 is about 44709.5018759995. The cubic root of 1998939558 is about 1259.6983316606.

The spelling of 1998939558 in words is "one billion, nine hundred ninety-eight million, nine hundred thirty-nine thousand, five hundred fifty-eight".