77808081481 has 27 divisors (see below), whose sum is σ = 86431886919. Its totient is φ = 70011959472.

The previous prime is 77808081469. The next prime is 77808081499. The reversal of 77808081481 is 18418080877.

The square root of 77808081481 is 278941.

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., 11510071225 + 66298010256 = 107285^2 + 257484^2 .

It is not a de Polignac number, because 77808081481 - 2²¹ = 77805984329 is a prime.

It is a super-2 number, since 2×77808081481² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77808031481) 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 26 ways as a sum of consecutive naturals, for example, 155927770 + ... + 155928268.

It is an arithmetic number, because the mean of its divisors is an integer number (3201180997).

Almost surely, 2^77808081481 is an apocalyptic number.

77808081481 is the 278941-st square number.

77808081481 is the 139471-st centered octagonal number.

It is an amenable number.

77808081481 is a deficient number, since it is larger than the sum of its proper divisors (8623805438).

77808081481 is an frugal number, since it uses more digits than its factorization.

77808081481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 802816, while the sum is 52.

The spelling of 77808081481 in words is "seventy-seven billion, eight hundred eight million, eighty-one thousand, four hundred eighty-one".