77680028161 has 4 divisors (see below), whose sum is σ = 77900085252. Its totient is φ = 77459971072.

The previous prime is 77680028149. The next prime is 77680028189. The reversal of 77680028161 is 16182008677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16182008677 = 691 ⋅23418247.

It can be written as a sum of positive squares in 2 ways, for example, as 29029344400 + 48650683761 = 170380^2 + 220569^2 .

It is a cyclic number.

It is not a de Polignac number, because 77680028161 - 2³¹ = 75532544513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77680028131) 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 3 ways as a sum of consecutive naturals, for example, 110028016 + ... + 110028721.

It is an arithmetic number, because the mean of its divisors is an integer number (19475021313).

Almost surely, 2^77680028161 is an apocalyptic number.

It is an amenable number.

77680028161 is a deficient number, since it is larger than the sum of its proper divisors (220057091).

77680028161 is a wasteful number, since it uses less digits than its factorization.

77680028161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220057090.

The product of its (nonzero) digits is 225792, while the sum is 46.

The spelling of 77680028161 in words is "seventy-seven billion, six hundred eighty million, twenty-eight thousand, one hundred sixty-one".