81065807 has 8 divisors (see below), whose sum is σ = 82016880. Its totient is φ = 80118720.

The previous prime is 81065801. The next prime is 81065819. The reversal of 81065807 is 70856018.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81065807 - 2⁴ = 81065791 is a prime.

It is a super-3 number, since 3×81065807³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81065801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60707 + ... + 62027.

It is an arithmetic number, because the mean of its divisors is an integer number (10252110).

Almost surely, 2^81065807 is an apocalyptic number.

81065807 is a deficient number, since it is larger than the sum of its proper divisors (951073).

81065807 is a wasteful number, since it uses less digits than its factorization.

81065807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1993.

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 81065807 is about 9003.6552021943. The cubic root of 81065807 is about 432.7920123594.

The spelling of 81065807 in words is "eighty-one million, sixty-five thousand, eight hundred seven".