1998856742400 has 1920 divisors, whose sum is σ = 8727579970560. Its totient is φ = 438581329920.

The previous prime is 1998856742387. The next prime is 1998856742431. The reversal of 1998856742400 is 42476588991.

1998856742400 is a `hidden beast` number, since 1 + 9 + 98 + 85 + 67 + 4 + 2 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

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, 12262924719 + ... + 12262924881.

It is an arithmetic number, because the mean of its divisors is an integer number (4545614568).

Almost surely, 2^{1998856742400} is an apocalyptic number.

1998856742400 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 1998856742400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4363789985280).

1998856742400 is an abundant number, since it is smaller than the sum of its proper divisors (6728723228160).

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

1998856742400 is a wasteful number, since it uses less digits than its factorization.

1998856742400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 63.

The spelling of 1998856742400 in words is "one trillion, nine hundred ninety-eight billion, eight hundred fifty-six million, seven hundred forty-two thousand, four hundred".