19911339887904 has 144 divisors (see below), whose sum is σ = 57159446486688. Its totient is φ = 6574234269696.

The previous prime is 19911339887851. The next prime is 19911339887927. The reversal of 19911339887904 is 40978893311991.

19911339887904 is a `hidden beast` number, since 199 + 11 + 339 + 8 + 8 + 7 + 90 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×19911339887904² (a number of 27 digits) contains 22 as substring.

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 23 ways as a sum of consecutive naturals, for example, 265812184 + ... + 265887080.

It is an arithmetic number, because the mean of its divisors is an integer number (396940600602).

Almost surely, 2^{19911339887904} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19911339887904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28579723243344).

19911339887904 is an abundant number, since it is smaller than the sum of its proper divisors (37248106598784).

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

19911339887904 is a wasteful number, since it uses less digits than its factorization.

19911339887904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83647 (or 83636 counting only the distinct ones).

The product of its (nonzero) digits is 105815808, while the sum is 72.

The spelling of 19911339887904 in words is "nineteen trillion, nine hundred eleven billion, three hundred thirty-nine million, eight hundred eighty-seven thousand, nine hundred four".