78555816577 has 16 divisors (see below), whose sum is σ = 90742361472. Its totient is φ = 66613703040.

The previous prime is 78555816557. The next prime is 78555816587. The reversal of 78555816577 is 77561855587.

It is a cyclic number.

It is not a de Polignac number, because 78555816577 - 2¹¹ = 78555814529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78555816557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141202 + ... + 420772.

It is an arithmetic number, because the mean of its divisors is an integer number (5671397592).

Almost surely, 2^78555816577 is an apocalyptic number.

It is an amenable number.

78555816577 is a deficient number, since it is larger than the sum of its proper divisors (12186544895).

78555816577 is a wasteful number, since it uses less digits than its factorization.

78555816577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280008.

The product of its digits is 82320000, while the sum is 64.

The spelling of 78555816577 in words is "seventy-eight billion, five hundred fifty-five million, eight hundred sixteen thousand, five hundred seventy-seven".