68515131840 has 224 divisors, whose sum is σ = 224670298944. Its totient is φ = 17677025280.

The previous prime is 68515131823. The next prime is 68515131851. The reversal of 68515131840 is 4813151586.

It is a junction number, because it is equal to n+sod(n) for n = 68515131792 and 68515131801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6423792 + ... + 6434448.

It is an arithmetic number, because the mean of its divisors is an integer number (1002992406).

Almost surely, 2^68515131840 is an apocalyptic number.

68515131840 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 68515131840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112335149472).

68515131840 is an abundant number, since it is smaller than the sum of its proper divisors (156155167104).

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

68515131840 is a wasteful number, since it uses less digits than its factorization.

68515131840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10895 (or 10885 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 42.

The spelling of 68515131840 in words is "sixty-eight billion, five hundred fifteen million, one hundred thirty-one thousand, eight hundred forty".