81712804 has 6 divisors (see below), whose sum is σ = 142997414. Its totient is φ = 40856400.

The previous prime is 81712801. The next prime is 81712819. The reversal of 81712804 is 40821718.

It can be written as a sum of positive squares in only one way, i.e., 67272804 + 14440000 = 8202^2 + 3800^2 .

It is not an unprimeable number, because it can be changed into a prime (81712801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10214097 + ... + 10214104.

Almost surely, 2^81712804 is an apocalyptic number.

It is an amenable number.

81712804 is a deficient number, since it is larger than the sum of its proper divisors (61284610).

81712804 is a wasteful number, since it uses less digits than its factorization.

81712804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20428205 (or 20428203 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 81712804 is about 9039.5134824834. The cubic root of 81712804 is about 433.9403529628.

The spelling of 81712804 in words is "eighty-one million, seven hundred twelve thousand, eight hundred four".