1913539438728 has 224 divisors, whose sum is σ = 5441167353600. Its totient is φ = 630556617600.

The previous prime is 1913539438721. The next prime is 1913539438751. The reversal of 1913539438728 is 8278349353191.

1913539438728 is a `hidden beast` number, since 1 + 9 + 13 + 539 + 4 + 3 + 87 + 2 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (1913539438721) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 205509193 + ... + 205518503.

Almost surely, 2^{1913539438728} is an apocalyptic number.

1913539438728 is a gapful number since it is divisible by the number (18) 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 1913539438728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2720583676800).

1913539438728 is an abundant number, since it is smaller than the sum of its proper divisors (3527627914872).

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

1913539438728 is a wasteful number, since it uses less digits than its factorization.

1913539438728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9735 (or 9716 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 63.

The spelling of 1913539438728 in words is "one trillion, nine hundred thirteen billion, five hundred thirty-nine million, four hundred thirty-eight thousand, seven hundred twenty-eight".