68509728 has 144 divisors (see below), whose sum is σ = 235872000. Its totient is φ = 18413568.

The previous prime is 68509717. The next prime is 68509733. The reversal of 68509728 is 82790586.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33273 + ... + 35271.

It is an arithmetic number, because the mean of its divisors is an integer number (1638000).

Almost surely, 2^68509728 is an apocalyptic number.

68509728 is a gapful number since it is divisible by the number (68) 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 68509728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117936000).

68509728 is an abundant number, since it is smaller than the sum of its proper divisors (167362272).

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

68509728 is a wasteful number, since it uses less digits than its factorization.

68509728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2039 (or 2028 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 68509728 is about 8277.0603477322. The cubic root of 68509728 is about 409.1828419920.

It can be divided in two parts, 68 and 509728, that added together give a square (509796 = 714²).

The spelling of 68509728 in words is "sixty-eight million, five hundred nine thousand, seven hundred twenty-eight".