68724864 has 144 divisors (see below), whose sum is σ = 214752330. Its totient is φ = 21086208.

The previous prime is 68724841. The next prime is 68724883. The reversal of 68724864 is 46842786.

It can be written as a sum of positive squares in 3 ways, for example, as 31270464 + 37454400 = 5592^2 + 6120^2 .

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 17 ways as a sum of consecutive naturals, for example, 194512 + ... + 194864.

Almost surely, 2^68724864 is an apocalyptic number.

68724864 is a gapful number since it is divisible by the number (64) 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 68724864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107376165).

68724864 is an abundant number, since it is smaller than the sum of its proper divisors (146027466).

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

68724864 is a wasteful number, since it uses less digits than its factorization.

68724864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 371 counting only the distinct ones).

The product of its digits is 516096, while the sum is 45.

The square root of 68724864 is about 8290.0460794859. The cubic root of 68724864 is about 409.6107032522.

The spelling of 68724864 in words is "sixty-eight million, seven hundred twenty-four thousand, eight hundred sixty-four".