81393486 has 8 divisors (see below), whose sum is σ = 162786984. Its totient is φ = 27131160.

The previous prime is 81393457. The next prime is 81393523. The reversal of 81393486 is 68439318.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

81393486 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6782785 + ... + 6782796.

It is an arithmetic number, because the mean of its divisors is an integer number (20348373).

Almost surely, 2^81393486 is an apocalyptic number.

81393486 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81393486 is a wasteful number, since it uses less digits than its factorization.

81393486 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13565586.

The product of its digits is 124416, while the sum is 42.

The square root of 81393486 is about 9021.8338490575. The cubic root of 81393486 is about 433.3743631104.

The spelling of 81393486 in words is "eighty-one million, three hundred ninety-three thousand, four hundred eighty-six".