81446680 has 64 divisors (see below), whose sum is σ = 218557440. Its totient is φ = 26708352.

The previous prime is 81446663. The next prime is 81446683. The reversal of 81446680 is 8664418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81446683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117 + ... + 12763.

It is an arithmetic number, because the mean of its divisors is an integer number (3414960).

Almost surely, 2^81446680 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 81446680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109278720).

81446680 is an abundant number, since it is smaller than the sum of its proper divisors (137110760).

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

81446680 is a wasteful number, since it uses less digits than its factorization.

81446680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12688 (or 12684 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 81446680 is about 9024.7814377967. The cubic root of 81446680 is about 433.4687518910.

The spelling of 81446680 in words is "eighty-one million, four hundred forty-six thousand, six hundred eighty".