77691651816 has 32 divisors (see below), whose sum is σ = 194274840960. Its totient is φ = 25891122432.

The previous prime is 77691651809. The next prime is 77691651859. The reversal of 77691651816 is 61815619677.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276240 + ... + 481343.

It is an arithmetic number, because the mean of its divisors is an integer number (6071088780).

Almost surely, 2^77691651816 is an apocalyptic number.

It is an amenable number.

77691651816 is an abundant number, since it is smaller than the sum of its proper divisors (116583189144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77691651816 is a wasteful number, since it uses less digits than its factorization.

77691651816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761865 (or 761861 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 57.

The spelling of 77691651816 in words is "seventy-seven billion, six hundred ninety-one million, six hundred fifty-one thousand, eight hundred sixteen".