81704767 has 4 divisors (see below), whose sum is σ = 82030536. Its totient is φ = 81379000.

The previous prime is 81704761. The next prime is 81704789. The reversal of 81704767 is 76740718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76740718 = 2 ⋅38370359.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81704767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81704761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162508 + ... + 163009.

It is an arithmetic number, because the mean of its divisors is an integer number (20507634).

Almost surely, 2^81704767 is an apocalyptic number.

81704767 is a deficient number, since it is larger than the sum of its proper divisors (325769).

81704767 is a wasteful number, since it uses less digits than its factorization.

81704767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325768.

The product of its (nonzero) digits is 65856, while the sum is 40.

The square root of 81704767 is about 9039.0689232907. The cubic root of 81704767 is about 433.9261255191.

The spelling of 81704767 in words is "eighty-one million, seven hundred four thousand, seven hundred sixty-seven".