77680361779 has 2 divisors, whose sum is σ = 77680361780. Its totient is φ = 77680361778.

The previous prime is 77680361777. The next prime is 77680361797. The reversal of 77680361779 is 97716308677.

Together with next prime (77680361797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77680361779 - 2¹ = 77680361777 is a prime.

It is a super-2 number, since 2×77680361779² (a number of 23 digits) contains 22 as substring.

Together with 77680361777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (77680361771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38840180889 + 38840180890.

It is an arithmetic number, because the mean of its divisors is an integer number (38840180890).

Almost surely, 2^77680361779 is an apocalyptic number.

77680361779 is a deficient number, since it is larger than the sum of its proper divisors (1).

77680361779 is an equidigital number, since it uses as much as digits as its factorization.

77680361779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18670176, while the sum is 61.

The spelling of 77680361779 in words is "seventy-seven billion, six hundred eighty million, three hundred sixty-one thousand, seven hundred seventy-nine".