81367072687811 has 4 divisors (see below), whose sum is σ = 81447713989800. Its totient is φ = 81286431385824.

The previous prime is 81367072687801. The next prime is 81367072687847. The reversal of 81367072687811 is 11878627076318.

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 81367072687811 - 2³⁴ = 81349892818627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81367072687801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40320649481 + ... + 40320651498.

It is an arithmetic number, because the mean of its divisors is an integer number (20361928497450).

Almost surely, 2^{81367072687811} is an apocalyptic number.

81367072687811 is a deficient number, since it is larger than the sum of its proper divisors (80641301989).

81367072687811 is a wasteful number, since it uses less digits than its factorization.

81367072687811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80641301988.

The product of its (nonzero) digits is 37933056, while the sum is 65.

The spelling of 81367072687811 in words is "eighty-one trillion, three hundred sixty-seven billion, seventy-two million, six hundred eighty-seven thousand, eight hundred eleven".