77425566565 has 16 divisors (see below), whose sum is σ = 94081532400. Its totient is φ = 61163963392.

The previous prime is 77425566511. The next prime is 77425566593. The reversal of 77425566565 is 56566552477.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 10115934084 + 67309632481 = 100578^2 + 259441^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77425566565 is a prime.

It is a super-3 number, since 3×77425566565³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102730 + ... + 406699.

It is an arithmetic number, because the mean of its divisors is an integer number (5880095775).

Almost surely, 2^77425566565 is an apocalyptic number.

It is an amenable number.

77425566565 is a deficient number, since it is larger than the sum of its proper divisors (16655965835).

77425566565 is a wasteful number, since it uses less digits than its factorization.

77425566565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509816.

The product of its digits is 52920000, while the sum is 58.

The spelling of 77425566565 in words is "seventy-seven billion, four hundred twenty-five million, five hundred sixty-six thousand, five hundred sixty-five".