81866795 has 4 divisors (see below), whose sum is σ = 98240160. Its totient is φ = 65493432.

The previous prime is 81866789. The next prime is 81866857. The reversal of 81866795 is 59766818.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81866795 - 2¹² = 81862699 is a prime.

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 3 ways as a sum of consecutive naturals, for example, 8186675 + ... + 8186684.

It is an arithmetic number, because the mean of its divisors is an integer number (24560040).

Almost surely, 2^81866795 is an apocalyptic number.

81866795 is a deficient number, since it is larger than the sum of its proper divisors (16373365).

81866795 is a wasteful number, since it uses less digits than its factorization.

81866795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16373364.

The product of its digits is 725760, while the sum is 50.

The square root of 81866795 is about 9048.0271330274. The cubic root of 81866795 is about 434.2127744713.

The spelling of 81866795 in words is "eighty-one million, eight hundred sixty-six thousand, seven hundred ninety-five".