81684976 has 20 divisors (see below), whose sum is σ = 158559544. Its totient is φ = 40766400.

The previous prime is 81684947. The next prime is 81684989. The reversal of 81684976 is 67948618.

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, 4666 + ... + 13606.

Almost surely, 2^81684976 is an apocalyptic number.

It is an amenable number.

81684976 is a deficient number, since it is larger than the sum of its proper divisors (76874568).

81684976 is a wasteful number, since it uses less digits than its factorization.

81684976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9520 (or 9514 counting only the distinct ones).

The product of its digits is 580608, while the sum is 49.

The square root of 81684976 is about 9037.9741092791. The cubic root of 81684976 is about 433.8910866600.

The spelling of 81684976 in words is "eighty-one million, six hundred eighty-four thousand, nine hundred seventy-six".