77968561 has 8 divisors (see below), whose sum is σ = 85412448. Its totient is φ = 70584000.

The previous prime is 77968549. The next prime is 77968567. The reversal of 77968561 is 16586977.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77968561 - 2⁷ = 77968433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77968567) 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 7 ways as a sum of consecutive naturals, for example, 12055 + ... + 17356.

It is an arithmetic number, because the mean of its divisors is an integer number (10676556).

Almost surely, 2^77968561 is an apocalyptic number.

It is an amenable number.

77968561 is a deficient number, since it is larger than the sum of its proper divisors (7443887).

77968561 is a wasteful number, since it uses less digits than its factorization.

77968561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29663.

The product of its digits is 635040, while the sum is 49.

The square root of 77968561 is about 8829.9808040561. The cubic root of 77968561 is about 427.2084552775.

The spelling of 77968561 in words is "seventy-seven million, nine hundred sixty-eight thousand, five hundred sixty-one".