19911440847168 has 168 divisors, whose sum is σ = 65078202302568. Its totient is φ = 5766209077248.

The previous prime is 19911440847139. The next prime is 19911440847187. The reversal of 19911440847168 is 86174804411991.

19911440847168 is a `hidden beast` number, since 1 + 9 + 9 + 114 + 40 + 8 + 471 + 6 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 9206786304 + 19902234060864 = 95952^2 + 4461192^2 .

It is a super-2 number, since 2×19911440847168² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78081921 + ... + 78336512.

It is an arithmetic number, because the mean of its divisors is an integer number (387370251801).

Almost surely, 2^{19911440847168} is an apocalyptic number.

19911440847168 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19911440847168 is an abundant number, since it is smaller than the sum of its proper divisors (45166761455400).

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

19911440847168 is a wasteful number, since it uses less digits than its factorization.

19911440847168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156418481 (or 156418468 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 63.

The spelling of 19911440847168 in words is "nineteen trillion, nine hundred eleven billion, four hundred forty million, eight hundred forty-seven thousand, one hundred sixty-eight".