81660146680 has 256 divisors, whose sum is σ = 239495823360. Its totient is φ = 24391065600.

The previous prime is 81660146677. The next prime is 81660146699. The reversal of 81660146680 is 8664106618.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a self number, because there is not a number n which added to its sum of digits gives 81660146680.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 3381850 + ... + 3405910.

It is an arithmetic number, because the mean of its divisors is an integer number (935530560).

Almost surely, 2^81660146680 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 81660146680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119747911680).

81660146680 is an abundant number, since it is smaller than the sum of its proper divisors (157835676680).

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

81660146680 is a wasteful number, since it uses less digits than its factorization.

81660146680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24150 (or 24146 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 46.

The spelling of 81660146680 in words is "eighty-one billion, six hundred sixty million, one hundred forty-six thousand, six hundred eighty".