77561544765 has 32 divisors (see below), whose sum is σ = 131080790016. Its totient is φ = 39100783680.

The previous prime is 77561544763. The next prime is 77561544803. The reversal of 77561544765 is 56744516577.

It is not a de Polignac number, because 77561544765 - 2¹ = 77561544763 is a prime.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77561544763) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1919529 + ... + 1959518.

It is an arithmetic number, because the mean of its divisors is an integer number (4096274688).

Almost surely, 2^77561544765 is an apocalyptic number.

It is an amenable number.

77561544765 is a deficient number, since it is larger than the sum of its proper divisors (53519245251).

77561544765 is a wasteful number, since it uses less digits than its factorization.

77561544765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3879129.

The product of its digits is 24696000, while the sum is 57.

The spelling of 77561544765 in words is "seventy-seven billion, five hundred sixty-one million, five hundred forty-four thousand, seven hundred sixty-five".