81186768 has 120 divisors (see below), whose sum is σ = 252761600. Its totient is φ = 24157440.

The previous prime is 81186751. The next prime is 81186821. The reversal of 81186768 is 86768118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57333 + ... + 58731.

Almost surely, 2^81186768 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 81186768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126380800).

81186768 is an abundant number, since it is smaller than the sum of its proper divisors (171574832).

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

81186768 is a wasteful number, since it uses less digits than its factorization.

81186768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1457 (or 1448 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 81186768 is about 9010.3700256982. The cubic root of 81186768 is about 433.0071665241.

The spelling of 81186768 in words is "eighty-one million, one hundred eighty-six thousand, seven hundred sixty-eight".