68128251920 has 40 divisors (see below), whose sum is σ = 158665409496. Its totient is φ = 27205326848.

The previous prime is 68128251901. The next prime is 68128251977. The reversal of 68128251920 is 2915282186.

It can be written as a sum of positive squares in 4 ways, for example, as 17138999056 + 50989252864 = 130916^2 + 225808^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 670607 + ... + 765486.

Almost surely, 2^68128251920 is an apocalyptic number.

It is an amenable number.

68128251920 is an abundant number, since it is smaller than the sum of its proper divisors (90537157576).

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

68128251920 is a wasteful number, since it uses less digits than its factorization.

68128251920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1436699 (or 1436693 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 68128251920 in words is "sixty-eight billion, one hundred twenty-eight million, two hundred fifty-one thousand, nine hundred twenty".