81166534600 has 96 divisors (see below), whose sum is σ = 190676233440. Its totient is φ = 32130432000.

The previous prime is 81166534591. The next prime is 81166534613. The reversal of 81166534600 is 643566118.

It is a super-3 number, since 3×81166534600³ (a number of 34 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

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 23 ways as a sum of consecutive naturals, for example, 7851435 + ... + 7861765.

It is an arithmetic number, because the mean of its divisors is an integer number (1986210765).

Almost surely, 2^81166534600 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 81166534600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95338116720).

81166534600 is an abundant number, since it is smaller than the sum of its proper divisors (109509698840).

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

81166534600 is a wasteful number, since it uses less digits than its factorization.

81166534600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10751 (or 10742 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 81166534600 in words is "eighty-one billion, one hundred sixty-six million, five hundred thirty-four thousand, six hundred".