81704807 has 4 divisors (see below), whose sum is σ = 86005080. Its totient is φ = 77404536.

The previous prime is 81704801. The next prime is 81704827. The reversal of 81704807 is 70840718.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81704807 - 2⁸ = 81704551 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 (81704801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2150108 + ... + 2150145.

It is an arithmetic number, because the mean of its divisors is an integer number (21501270).

Almost surely, 2^81704807 is an apocalyptic number.

81704807 is a deficient number, since it is larger than the sum of its proper divisors (4300273).

81704807 is a wasteful number, since it uses less digits than its factorization.

81704807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4300272.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 81704807 is about 9039.0711359077. The cubic root of 81704807 is about 433.9261963311.

The spelling of 81704807 in words is "eighty-one million, seven hundred four thousand, eight hundred seven".