80866865641 has 9 divisors (see below), whose sum is σ = 81332189271. Its totient is φ = 80404194024.

The previous prime is 80866865579. The next prime is 80866865647. The reversal of 80866865641 is 14656866808.

The square root of 80866865641 is 284371.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5450721241 + 75416144400 = 73829^2 + 274620^2 .

It is not a de Polignac number, because 80866865641 - 2⁹ = 80866865129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80866865647) 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 8 ways as a sum of consecutive naturals, for example, 56589115 + ... + 56590543.

It is an arithmetic number, because the mean of its divisors is an integer number (9036909919).

Almost surely, 2^80866865641 is an apocalyptic number.

80866865641 is the 284371-st square number.

80866865641 is the 142186-th centered octagonal number.

It is an amenable number.

80866865641 is a deficient number, since it is larger than the sum of its proper divisors (465323630).

80866865641 is an frugal number, since it uses more digits than its factorization.

80866865641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3256 (or 1628 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 58.

The spelling of 80866865641 in words is "eighty billion, eight hundred sixty-six million, eight hundred sixty-five thousand, six hundred forty-one".