77815760561 has 16 divisors (see below), whose sum is σ = 97164334080. Its totient is φ = 60543606480.

The previous prime is 77815760557. The next prime is 77815760567. The reversal of 77815760561 is 16506751877.

It is not a de Polignac number, because 77815760561 - 2² = 77815760557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77815760567) by changing a digit.

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, 716021 + ... + 817506.

It is an arithmetic number, because the mean of its divisors is an integer number (6072770880).

Almost surely, 2^77815760561 is an apocalyptic number.

It is an amenable number.

77815760561 is a deficient number, since it is larger than the sum of its proper divisors (19348573519).

77815760561 is a wasteful number, since it uses less digits than its factorization.

77815760561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534204.

The product of its (nonzero) digits is 2469600, while the sum is 53.

The spelling of 77815760561 in words is "seventy-seven billion, eight hundred fifteen million, seven hundred sixty thousand, five hundred sixty-one".