1998555599040 has 1344 divisors, whose sum is σ = 8721269222400. Its totient is φ = 381157539840.

The previous prime is 1998555598999. The next prime is 1998555599093. The reversal of 1998555599040 is 409955558991.

It is a tau number, because it is divible by the number of its divisors (1344).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1338616534 + ... + 1338618026.

It is an arithmetic number, because the mean of its divisors is an integer number (6489039600).

Almost surely, 2^{1998555599040} is an apocalyptic number.

1998555599040 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 1998555599040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4360634611200).

1998555599040 is an abundant number, since it is smaller than the sum of its proper divisors (6722713623360).

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

1998555599040 is a wasteful number, since it uses less digits than its factorization.

1998555599040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1750 (or 1733 counting only the distinct ones).

The product of its (nonzero) digits is 131220000, while the sum is 69.

The spelling of 1998555599040 in words is "one trillion, nine hundred ninety-eight billion, five hundred fifty-five million, five hundred ninety-nine thousand, forty".