81279527358240 has 1344 divisors, whose sum is σ = 310716663344640. Its totient is φ = 20018156175360.

The previous prime is 81279527358209. The next prime is 81279527358361. The reversal of 81279527358240 is 4285372597218.

81279527358240 is a `hidden beast` number, since 8 + 1 + 2 + 7 + 9 + 5 + 2 + 7 + 3 + 582 + 40 = 666.

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 223 ways as a sum of consecutive naturals, for example, 29268823732 + ... + 29268826508.

It is an arithmetic number, because the mean of its divisors is an integer number (231187993560).

Almost surely, 2^{81279527358240} is an apocalyptic number.

81279527358240 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 81279527358240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155358331672320).

81279527358240 is an abundant number, since it is smaller than the sum of its proper divisors (229437135986400).

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

81279527358240 is a wasteful number, since it uses less digits than its factorization.

81279527358240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3157 (or 3134 counting only the distinct ones).

The product of its (nonzero) digits is 67737600, while the sum is 63.

The spelling of 81279527358240 in words is "eighty-one trillion, two hundred seventy-nine billion, five hundred twenty-seven million, three hundred fifty-eight thousand, two hundred forty".