78806705077 has 4 divisors (see below), whose sum is σ = 78925929196. Its totient is φ = 78687480960.

The previous prime is 78806705069. The next prime is 78806705083. The reversal of 78806705077 is 77050760887.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58993608996 + 19813096081 = 242886^2 + 140759^2 .

It is a cyclic number.

It is not a de Polignac number, because 78806705077 - 2³ = 78806705069 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 (78806705057) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59611068 + ... + 59612389.

It is an arithmetic number, because the mean of its divisors is an integer number (19731482299).

Almost surely, 2^78806705077 is an apocalyptic number.

It is an amenable number.

78806705077 is a deficient number, since it is larger than the sum of its proper divisors (119224119).

78806705077 is a wasteful number, since it uses less digits than its factorization.

78806705077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119224118.

The product of its (nonzero) digits is 4609920, while the sum is 55.

The spelling of 78806705077 in words is "seventy-eight billion, eight hundred six million, seven hundred five thousand, seventy-seven".