81706916 has 12 divisors (see below), whose sum is σ = 150512880. Its totient is φ = 38703240.

The previous prime is 81706909. The next prime is 81706939. The reversal of 81706916 is 61960718.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a self number, because there is not a number n which added to its sum of digits gives 81706916.

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, 537470 + ... + 537621.

It is an arithmetic number, because the mean of its divisors is an integer number (12542740).

Almost surely, 2^81706916 is an apocalyptic number.

It is an amenable number.

81706916 is a deficient number, since it is larger than the sum of its proper divisors (68805964).

81706916 is a wasteful number, since it uses less digits than its factorization.

81706916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1075114 (or 1075112 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 81706916 is about 9039.1877953719. The cubic root of 81706916 is about 433.9299298629.

The spelling of 81706916 in words is "eighty-one million, seven hundred six thousand, nine hundred sixteen".