77699359681 has 2 divisors, whose sum is σ = 77699359682. Its totient is φ = 77699359680.

The previous prime is 77699359669. The next prime is 77699359693. The reversal of 77699359681 is 18695399677.

It is a balanced prime because it is at equal distance from previous prime (77699359669) and next prime (77699359693).

It can be written as a sum of positive squares in only one way, i.e., 63423889281 + 14275470400 = 251841^2 + 119480^2 .

It is an emirp because it is prime and its reverse (18695399677) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77699359681 - 2⁵ = 77699359649 is a prime.

It is a super-2 number, since 2×77699359681² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 77699359681.

It is not a weakly prime, because it can be changed into another prime (77699359631) 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 as a sum of consecutive naturals, namely, 38849679840 + 38849679841.

It is an arithmetic number, because the mean of its divisors is an integer number (38849679841).

Almost surely, 2^77699359681 is an apocalyptic number.

It is an amenable number.

77699359681 is a deficient number, since it is larger than the sum of its proper divisors (1).

77699359681 is an equidigital number, since it uses as much as digits as its factorization.

77699359681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 154314720, while the sum is 70.

The spelling of 77699359681 in words is "seventy-seven billion, six hundred ninety-nine million, three hundred fifty-nine thousand, six hundred eighty-one".