77968109 has 2 divisors, whose sum is σ = 77968110. Its totient is φ = 77968108.

The previous prime is 77968081. The next prime is 77968117. The reversal of 77968109 is 90186977.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46854025 + 31114084 = 6845^2 + 5578^2 .

It is a cyclic number.

It is not a de Polignac number, because 77968109 - 2²⁰ = 76919533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77962109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38984054 + 38984055.

It is an arithmetic number, because the mean of its divisors is an integer number (38984055).

Almost surely, 2^77968109 is an apocalyptic number.

It is an amenable number.

77968109 is a deficient number, since it is larger than the sum of its proper divisors (1).

77968109 is an equidigital number, since it uses as much as digits as its factorization.

77968109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 77968109 is about 8829.9552093994. The cubic root of 77968109 is about 427.2076297371.

The spelling of 77968109 in words is "seventy-seven million, nine hundred sixty-eight thousand, one hundred nine".