81293142865968 has 480 divisors, whose sum is σ = 258284336244480. Its totient is φ = 24548114119680.

The previous prime is 81293142865937. The next prime is 81293142865969. The reversal of 81293142865968 is 86956824139218.

81293142865968 is a `hidden beast` number, since 8 + 1 + 2 + 9 + 3 + 1 + 4 + 28 + 6 + 596 + 8 = 666.

It is a super-3 number, since 3×81293142865968³ (a number of 43 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 81293142865896 and 81293142865905.

It is not an unprimeable number, because it can be changed into a prime (81293142865969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 29064404346 + ... + 29064407142.

It is an arithmetic number, because the mean of its divisors is an integer number (538092367176).

Almost surely, 2^{81293142865968} is an apocalyptic number.

81293142865968 is a gapful number since it is divisible by the number (88) 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 81293142865968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129142168122240).

81293142865968 is an abundant number, since it is smaller than the sum of its proper divisors (176991193378512).

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

81293142865968 is a wasteful number, since it uses less digits than its factorization.

81293142865968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4967 (or 4949 counting only the distinct ones).

The product of its digits is 358318080, while the sum is 72.

The spelling of 81293142865968 in words is "eighty-one trillion, two hundred ninety-three billion, one hundred forty-two million, eight hundred sixty-five thousand, nine hundred sixty-eight".