81217088013600 has 1152 divisors, whose sum is σ = 376113227212800. Its totient is φ = 16420149964800.

The previous prime is 81217088013587. The next prime is 81217088013617. The reversal of 81217088013600 is 631088071218.

It is a happy number.

81217088013600 is a `hidden beast` number, since 8 + 1 + 21 + 7 + 0 + 8 + 8 + 0 + 13 + 600 = 666.

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

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 60878511 + ... + 62198289.

It is an arithmetic number, because the mean of its divisors is an integer number (326487176400).

Almost surely, 2^{81217088013600} is an apocalyptic number.

81217088013600 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 81217088013600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188056613606400).

81217088013600 is an abundant number, since it is smaller than the sum of its proper divisors (294896139199200).

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

81217088013600 is a wasteful number, since it uses less digits than its factorization.

81217088013600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1319863 (or 1319844 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The spelling of 81217088013600 in words is "eighty-one trillion, two hundred seventeen billion, eighty-eight million, thirteen thousand, six hundred".