77939605771 has 4 divisors (see below), whose sum is σ = 77973539112. Its totient is φ = 77905672432.

The previous prime is 77939605763. The next prime is 77939605811. The reversal of 77939605771 is 17750693977.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17750693977 = 67 ⋅264935731.

It is a cyclic number.

It is not a de Polignac number, because 77939605771 - 2³ = 77939605763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77939605721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16963225 + ... + 16967818.

It is an arithmetic number, because the mean of its divisors is an integer number (19493384778).

Almost surely, 2^77939605771 is an apocalyptic number.

77939605771 is a deficient number, since it is larger than the sum of its proper divisors (33933341).

77939605771 is a wasteful number, since it uses less digits than its factorization.

77939605771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33933340.

The product of its (nonzero) digits is 17503290, while the sum is 61.

The spelling of 77939605771 in words is "seventy-seven billion, nine hundred thirty-nine million, six hundred five thousand, seven hundred seventy-one".