81466523712 has 336 divisors, whose sum is σ = 278510016512. Its totient is φ = 23128312320.

The previous prime is 81466523689. The next prime is 81466523753. The reversal of 81466523712 is 21732566418.

81466523712 is a `hidden beast` number, since 81 + 46 + 6 + 523 + 7 + 1 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17742537 + ... + 17747127.

Almost surely, 2^81466523712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81466523712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139255008256).

81466523712 is an abundant number, since it is smaller than the sum of its proper divisors (197043492800).

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

81466523712 is a wasteful number, since it uses less digits than its factorization.

81466523712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4788 (or 4766 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 81466523712 in words is "eighty-one billion, four hundred sixty-six million, five hundred twenty-three thousand, seven hundred twelve".