81684886 has 8 divisors (see below), whose sum is σ = 122625000. Its totient is φ = 40809888.

The previous prime is 81684853. The next prime is 81684893. The reversal of 81684886 is 68848618.

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

It is a congruent number.

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, 13011 + ... + 18238.

It is an arithmetic number, because the mean of its divisors is an integer number (15328125).

Almost surely, 2^81684886 is an apocalyptic number.

81684886 is a deficient number, since it is larger than the sum of its proper divisors (40940114).

81684886 is a wasteful number, since it uses less digits than its factorization.

81684886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32558.

The product of its digits is 589824, while the sum is 49.

The square root of 81684886 is about 9037.9691302859. The cubic root of 81684886 is about 433.8909273071.

The spelling of 81684886 in words is "eighty-one million, six hundred eighty-four thousand, eight hundred eighty-six".