1998556560 has 960 divisors, whose sum is σ = 9359400960. Its totient is φ = 368824320.

The previous prime is 1998556559. The next prime is 1998556579. The reversal of 1998556560 is 656558991.

1998556560 is a `hidden beast` number, since 19 + 9 + 8 + 5 + 565 + 60 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1998556497 and 1998556506.

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 33873811 + ... + 33873869.

It is an arithmetic number, because the mean of its divisors is an integer number (9749376).

Almost surely, 2^1998556560 is an apocalyptic number.

1998556560 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 1998556560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4679700480).

1998556560 is an abundant number, since it is smaller than the sum of its proper divisors (7360844400).

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

1998556560 is a wasteful number, since it uses less digits than its factorization.

1998556560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 2916000, while the sum is 54.

The square root of 1998556560 is about 44705.2184873310. The cubic root of 1998556560 is about 1259.6178735403.

The spelling of 1998556560 in words is "one billion, nine hundred ninety-eight million, five hundred fifty-six thousand, five hundred sixty".