81976 has 8 divisors (see below), whose sum is σ = 153720. Its totient is φ = 40984.

The previous prime is 81973. The next prime is 82003. The reversal of 81976 is 67918.

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5116 + ... + 5131.

It is an arithmetic number, because the mean of its divisors is an integer number (19215).

2⁸¹⁹⁷⁶ is an apocalyptic number.

It is an amenable number.

81976 is a deficient number, since it is larger than the sum of its proper divisors (71744).

81976 is a wasteful number, since it uses less digits than its factorization.

81976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10253 (or 10249 counting only the distinct ones).

The product of its digits is 3024, while the sum is 31.

The square root of 81976 is about 286.3145123811. The cubic root of 81976 is about 43.4405759256.

The spelling of 81976 in words is "eighty-one thousand, nine hundred seventy-six".