50391081808128 has 360 divisors, whose sum is σ = 153969872912856. Its totient is φ = 16382236262400.

The previous prime is 50391081808117. The next prime is 50391081808139. The reversal of 50391081808128 is 82180818019305.

50391081808128 is a `hidden beast` number, since 5 + 0 + 391 + 0 + 81 + 80 + 81 + 28 = 666.

It is an interprime number because it is at equal distance from previous prime (50391081808117) and next prime (50391081808139).

It can be written as a sum of positive squares in 4 ways, for example, as 424957964544 + 49966123843584 = 651888^2 + 7068672^2 .

It is a super-2 number, since 2×50391081808128² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3513770238 + ... + 3513784578.

Almost surely, 2^{50391081808128} 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 50391081808128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76984936456428).

50391081808128 is an abundant number, since it is smaller than the sum of its proper divisors (103578791104728).

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

50391081808128 is a wasteful number, since it uses less digits than its factorization.

50391081808128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18543 (or 18520 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 54.

The spelling of 50391081808128 in words is "fifty trillion, three hundred ninety-one billion, eighty-one million, eight hundred eight thousand, one hundred twenty-eight".