81766928 has 10 divisors (see below), whose sum is σ = 158423454. Its totient is φ = 40883456.

The previous prime is 81766903. The next prime is 81766973. The reversal of 81766928 is 82966718.

It can be written as a sum of positive squares in only one way, i.e., 81504784 + 262144 = 9028^2 + 512^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2555201 + ... + 2555232.

Almost surely, 2^81766928 is an apocalyptic number.

It is an amenable number.

81766928 is a deficient number, since it is larger than the sum of its proper divisors (76656526).

81766928 is a wasteful number, since it uses less digits than its factorization.

81766928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5110441 (or 5110435 counting only the distinct ones).

The product of its digits is 290304, while the sum is 47.

The square root of 81766928 is about 9042.5067320959. The cubic root of 81766928 is about 434.0361413127.

The spelling of 81766928 in words is "eighty-one million, seven hundred sixty-six thousand, nine hundred twenty-eight".