1998631065600 has 1152 divisors, whose sum is σ = 8009477985600. Its totient is φ = 491612405760.

The previous prime is 1998631065581. The next prime is 1998631065659. The reversal of 1998631065600 is 65601368991.

1998631065600 is a `hidden beast` number, since 1 + 9 + 9 + 8 + 63 + 10 + 6 + 560 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a super-2 number, since 2×1998631065600² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1455666514 + ... + 1455667886.

Almost surely, 2^{1998631065600} is an apocalyptic number.

1998631065600 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 1998631065600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4004738992800).

1998631065600 is an abundant number, since it is smaller than the sum of its proper divisors (6010846920000).

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

1998631065600 is an equidigital number, since it uses as much as digits as its factorization.

1998631065600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439 (or 1396 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The spelling of 1998631065600 in words is "one trillion, nine hundred ninety-eight billion, six hundred thirty-one million, sixty-five thousand, six hundred".