1998558668 has 12 divisors (see below), whose sum is σ = 3545388840. Its totient is φ = 985590432.

The previous prime is 1998558659. The next prime is 1998558671. The reversal of 1998558668 is 8668558991.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3421898 + ... + 3422481.

It is an arithmetic number, because the mean of its divisors is an integer number (295449070).

Almost surely, 2^1998558668 is an apocalyptic number.

It is an amenable number.

1998558668 is a deficient number, since it is larger than the sum of its proper divisors (1546830172).

1998558668 is a wasteful number, since it uses less digits than its factorization.

1998558668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6844456 (or 6844454 counting only the distinct ones).

The product of its digits is 37324800, while the sum is 65.

The square root of 1998558668 is about 44705.2420639907. The cubic root of 1998558668 is about 1259.6183164055.

The spelling of 1998558668 in words is "one billion, nine hundred ninety-eight million, five hundred fifty-eight thousand, six hundred sixty-eight".