81969318624960 has 336 divisors, whose sum is σ = 304022959400160. Its totient is φ = 20150817914880.

The previous prime is 81969318624923. The next prime is 81969318624961. The reversal of 81969318624960 is 6942681396918.

81969318624960 is a `hidden beast` number, since 8 + 1 + 9 + 6 + 9 + 318 + 6 + 249 + 60 = 666.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (81969318624961) 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 47 ways as a sum of consecutive naturals, for example, 27367855 + ... + 30214865.

It is an arithmetic number, because the mean of its divisors is an integer number (904830236310).

Almost surely, 2^{81969318624960} is an apocalyptic number.

81969318624960 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 81969318624960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152011479700080).

81969318624960 is an abundant number, since it is smaller than the sum of its proper divisors (222053640775200).

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

81969318624960 is a wasteful number, since it uses less digits than its factorization.

81969318624960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2847816 (or 2847803 counting only the distinct ones).

The product of its (nonzero) digits is 241864704, while the sum is 72.

The spelling of 81969318624960 in words is "eighty-one trillion, nine hundred sixty-nine billion, three hundred eighteen million, six hundred twenty-four thousand, nine hundred sixty".