19644021030816 has 864 divisors, whose sum is σ = 70614435685248. Its totient is φ = 5134212034560.

The previous prime is 19644021030797. The next prime is 19644021030817. The reversal of 19644021030816 is 61803012044691.

19644021030816 is a `hidden beast` number, since 1 + 9 + 64 + 402 + 103 + 0 + 81 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (19644021030817) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 12898240231 + ... + 12898241753.

It is an arithmetic number, because the mean of its divisors is an integer number (81729670932).

Almost surely, 2^{19644021030816} is an apocalyptic number.

19644021030816 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 19644021030816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35307217842624).

19644021030816 is an abundant number, since it is smaller than the sum of its proper divisors (50970414654432).

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

19644021030816 is a wasteful number, since it uses less digits than its factorization.

19644021030816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2154 (or 2136 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 19644021030816 in words is "nineteen trillion, six hundred forty-four billion, twenty-one million, thirty thousand, eight hundred sixteen".