81386368 has 32 divisors (see below), whose sum is σ = 185301360. Its totient is φ = 34879488.

The previous prime is 81386339. The next prime is 81386381. The reversal of 81386368 is 86368318.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 44521 + ... + 46312.

Almost surely, 2^81386368 is an apocalyptic number.

It is an amenable number.

81386368 is an abundant number, since it is smaller than the sum of its proper divisors (103914992).

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

81386368 is an equidigital number, since it uses as much as digits as its factorization.

81386368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90854 (or 90842 counting only the distinct ones).

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

The square root of 81386368 is about 9021.4393530079. The cubic root of 81386368 is about 433.3617296316.

The spelling of 81386368 in words is "eighty-one million, three hundred eighty-six thousand, three hundred sixty-eight".