19966834457856 has 576 divisors, whose sum is σ = 70981433994240. Its totient is φ = 5455230197760.

The previous prime is 19966834457839. The next prime is 19966834457893. The reversal of 19966834457856 is 65875443866991.

19966834457856 is a `hidden beast` number, since 1 + 9 + 9 + 6 + 6 + 8 + 34 + 4 + 578 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 42266995 + ... + 42736781.

It is an arithmetic number, because the mean of its divisors is an integer number (123231656240).

Almost surely, 2^{19966834457856} is an apocalyptic number.

19966834457856 is a gapful number since it is divisible by the number (16) 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 19966834457856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35490716997120).

19966834457856 is an abundant number, since it is smaller than the sum of its proper divisors (51014599536384).

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

19966834457856 is a wasteful number, since it uses less digits than its factorization.

19966834457856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469879 (or 469859 counting only the distinct ones).

The product of its digits is 9405849600, while the sum is 81.

The spelling of 19966834457856 in words is "nineteen trillion, nine hundred sixty-six billion, eight hundred thirty-four million, four hundred fifty-seven thousand, eight hundred fifty-six".