68851720440 has 640 divisors, whose sum is σ = 254529792000. Its totient is φ = 16628198400.

The previous prime is 68851720363. The next prime is 68851720463. The reversal of 68851720440 is 4402715886.

68851720440 is a `hidden beast` number, since 68 + 85 + 1 + 72 + 0 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 208011075 + ... + 208011405.

It is an arithmetic number, because the mean of its divisors is an integer number (397702800).

Almost surely, 2^68851720440 is an apocalyptic number.

68851720440 is a gapful number since it is divisible by the number (60) 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 68851720440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127264896000).

68851720440 is an abundant number, since it is smaller than the sum of its proper divisors (185678071560).

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

68851720440 is a wasteful number, since it uses less digits than its factorization.

68851720440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513 (or 500 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The spelling of 68851720440 in words is "sixty-eight billion, eight hundred fifty-one million, seven hundred twenty thousand, four hundred forty".