19999256120064 has 720 divisors, whose sum is σ = 68077432751328. Its totient is φ = 5784973737984.

The previous prime is 19999256120029. The next prime is 19999256120069. The reversal of 19999256120064 is 46002165299991.

19999256120064 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 9 + 2 + 5 + 612 + 0 + 0 + 6 + 4 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 19999256119983 and 19999256120010.

It is not an unprimeable number, because it can be changed into a prime (19999256120069) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 5118824799 + ... + 5118828705.

Almost surely, 2^{19999256120064} 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 19999256120064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34038716375664).

19999256120064 is an abundant number, since it is smaller than the sum of its proper divisors (48078176631264).

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

19999256120064 is a wasteful number, since it uses less digits than its factorization.

19999256120064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5082 (or 5059 counting only the distinct ones).

The product of its (nonzero) digits is 18895680, while the sum is 63.

The spelling of 19999256120064 in words is "nineteen trillion, nine hundred ninety-nine billion, two hundred fifty-six million, one hundred twenty thousand, sixty-four".