81661682 has 8 divisors (see below), whose sum is σ = 122543616. Its totient is φ = 40813812.

The previous prime is 81661673. The next prime is 81661703. The reversal of 81661682 is 28616618.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1298 + ... + 12845.

It is an arithmetic number, because the mean of its divisors is an integer number (15317952).

Almost surely, 2^81661682 is an apocalyptic number.

81661682 is a deficient number, since it is larger than the sum of its proper divisors (40881934).

81661682 is a wasteful number, since it uses less digits than its factorization.

81661682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17032.

The product of its digits is 27648, while the sum is 38.

The square root of 81661682 is about 9036.6853436423. The cubic root of 81661682 is about 433.8498386837.

The spelling of 81661682 in words is "eighty-one million, six hundred sixty-one thousand, six hundred eighty-two".