77666539207 has 4 divisors (see below), whose sum is σ = 77701732416. Its totient is φ = 77631346000.

The previous prime is 77666539177. The next prime is 77666539211. The reversal of 77666539207 is 70293566677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70293566677 = 127 ⋅553492651.

It is a cyclic number.

It is not a de Polignac number, because 77666539207 - 2³¹ = 75519055559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77666539217) 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 3 ways as a sum of consecutive naturals, for example, 17593294 + ... + 17597707.

It is an arithmetic number, because the mean of its divisors is an integer number (19425433104).

Almost surely, 2^77666539207 is an apocalyptic number.

77666539207 is a deficient number, since it is larger than the sum of its proper divisors (35193209).

77666539207 is a wasteful number, since it uses less digits than its factorization.

77666539207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35193208.

The product of its (nonzero) digits is 20003760, while the sum is 58.

The spelling of 77666539207 in words is "seventy-seven billion, six hundred sixty-six million, five hundred thirty-nine thousand, two hundred seven".