77800218077605 has 4 divisors (see below), whose sum is σ = 93360261693132. Its totient is φ = 62240174462080.

The previous prime is 77800218077591. The next prime is 77800218077639. The reversal of 77800218077605 is 50677081200877.

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 28089130806724 + 49711087270881 = 5299918^2 + 7050609^2 .

It is not a de Polignac number, because 77800218077605 - 2²³ = 77800209688997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77800218077605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7780021807756 + ... + 7780021807765.

It is an arithmetic number, because the mean of its divisors is an integer number (23340065423283).

Almost surely, 2^{77800218077605} is an apocalyptic number.

It is an amenable number.

77800218077605 is a deficient number, since it is larger than the sum of its proper divisors (15560043615527).

77800218077605 is a wasteful number, since it uses less digits than its factorization.

77800218077605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15560043615526.

The product of its (nonzero) digits is 9219840, while the sum is 58.

The spelling of 77800218077605 in words is "seventy-seven trillion, eight hundred billion, two hundred eighteen million, seventy-seven thousand, six hundred five".