81946384 has 40 divisors (see below), whose sum is σ = 173183360. Its totient is φ = 37335168.

The previous prime is 81946349. The next prime is 81946391. The reversal of 81946384 is 48364918.

It is a self number, because there is not a number n which added to its sum of digits gives 81946384.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13939 + ... + 18925.

It is an arithmetic number, because the mean of its divisors is an integer number (4329584).

Almost surely, 2^81946384 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 81946384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86591680).

81946384 is an abundant number, since it is smaller than the sum of its proper divisors (91236976).

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

81946384 is a wasteful number, since it uses less digits than its factorization.

81946384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5087 (or 5081 counting only the distinct ones).

The product of its digits is 165888, while the sum is 43.

The square root of 81946384 is about 9052.4242057031. The cubic root of 81946384 is about 434.3534394281.

The spelling of 81946384 in words is "eighty-one million, nine hundred forty-six thousand, three hundred eighty-four".