19998563246640 has 480 divisors, whose sum is σ = 76410721400832. Its totient is φ = 4643371008000.

The previous prime is 19998563246639. The next prime is 19998563246677. The reversal of 19998563246640 is 4664236589991.

19998563246640 is a `hidden beast` number, since 1 + 9 + 9 + 98 + 5 + 6 + 32 + 466 + 40 = 666.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (72).

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, 23395575 + ... + 24235305.

Almost surely, 2^{19998563246640} is an apocalyptic number.

19998563246640 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 19998563246640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38205360700416).

19998563246640 is an abundant number, since it is smaller than the sum of its proper divisors (56412158154192).

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

19998563246640 is a wasteful number, since it uses less digits than its factorization.

19998563246640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 839889 (or 839880 counting only the distinct ones).

The product of its (nonzero) digits is 604661760, while the sum is 72.

The spelling of 19998563246640 in words is "nineteen trillion, nine hundred ninety-eight billion, five hundred sixty-three million, two hundred forty-six thousand, six hundred forty".