80021660161 has 3 divisors (see below), whose sum is σ = 80021943043. Its totient is φ = 80021377280.

The previous prime is 80021660123. The next prime is 80021660203. The reversal of 80021660161 is 16106612008.

The square root of 80021660161 is 282881.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 2670925761 + 77350734400 = 51681^2 + 278120^2 .

It is not a de Polignac number, because 80021660161 - 2³⁵ = 45661921793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80021660861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 141441 + ... + 424321.

Almost surely, 2^80021660161 is an apocalyptic number.

80021660161 is the 282881-st square number.

80021660161 is the 141441-st centered octagonal number.

It is an amenable number.

80021660161 is a deficient number, since it is larger than the sum of its proper divisors (282882).

80021660161 is an frugal number, since it uses more digits than its factorization.

80021660161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565762 (or 282881 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The spelling of 80021660161 in words is "eighty billion, twenty-one million, six hundred sixty thousand, one hundred sixty-one".