81347079940560 has 240 divisors, whose sum is σ = 312311691843840. Its totient is φ = 18588029091840.

The previous prime is 81347079940487. The next prime is 81347079940561. The reversal of 81347079940560 is 6504997074318.

81347079940560 is a `hidden beast` number, since 8 + 1 + 3 + 470 + 79 + 9 + 40 + 56 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-3 number, since 3×81347079940560³ (a number of 43 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81347079940561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14353965 + ... + 19202355.

It is an arithmetic number, because the mean of its divisors is an integer number (1301298716016).

Almost surely, 2^{81347079940560} is an apocalyptic number.

81347079940560 is a gapful number since it is divisible by the number (80) 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 81347079940560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156155845921920).

81347079940560 is an abundant number, since it is smaller than the sum of its proper divisors (230964611903280).

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

81347079940560 is a wasteful number, since it uses less digits than its factorization.

81347079940560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4851746 (or 4851737 counting only the distinct ones).

The product of its (nonzero) digits is 45722880, while the sum is 63.

The spelling of 81347079940560 in words is "eighty-one trillion, three hundred forty-seven billion, seventy-nine million, nine hundred forty thousand, five hundred sixty".