81340768 has 12 divisors (see below), whose sum is σ = 160139700. Its totient is φ = 40670368.

The previous prime is 81340751. The next prime is 81340769. The reversal of 81340768 is 86704318.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81340769) by changing a digit.

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 as a sum of consecutive naturals, namely, 1270918 + ... + 1270981.

It is an arithmetic number, because the mean of its divisors is an integer number (13344975).

Almost surely, 2^81340768 is an apocalyptic number.

It is an amenable number.

81340768 is a deficient number, since it is larger than the sum of its proper divisors (78798932).

81340768 is a wasteful number, since it uses less digits than its factorization.

81340768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2541909 (or 2541901 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 81340768 is about 9018.9116860074. The cubic root of 81340768 is about 433.2807783732.

The spelling of 81340768 in words is "eighty-one million, three hundred forty thousand, seven hundred sixty-eight".