81662948005266 has 96 divisors (see below), whose sum is σ = 190009755936000. Its totient is φ = 25268821254144.

The previous prime is 81662948005189. The next prime is 81662948005349. The reversal of 81662948005266 is 66250084926618.

81662948005266 is a `hidden beast` number, since 8 + 1 + 6 + 6 + 29 + 4 + 80 + 0 + 526 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11009575 + ... + 16868213.

It is an arithmetic number, because the mean of its divisors is an integer number (1979268291000).

Almost surely, 2^{81662948005266} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81662948005266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95004877968000).

81662948005266 is an abundant number, since it is smaller than the sum of its proper divisors (108346807930734).

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

81662948005266 is a wasteful number, since it uses less digits than its factorization.

81662948005266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5859488 (or 5859485 counting only the distinct ones).

The product of its (nonzero) digits is 59719680, while the sum is 63.

The spelling of 81662948005266 in words is "eighty-one trillion, six hundred sixty-two billion, nine hundred forty-eight million, five thousand, two hundred sixty-six".