77851668516 has 24 divisors (see below), whose sum is σ = 181658635200. Its totient is φ = 25949878752.

The previous prime is 77851668511. The next prime is 77851668523. The reversal of 77851668516 is 61586615877.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 77851668516.

It is not an unprimeable number, because it can be changed into a prime (77851668511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 647185 + ... + 757991.

It is an arithmetic number, because the mean of its divisors is an integer number (7569109800).

Almost surely, 2^77851668516 is an apocalyptic number.

It is an amenable number.

77851668516 is an abundant number, since it is smaller than the sum of its proper divisors (103806966684).

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

77851668516 is a wasteful number, since it uses less digits than its factorization.

77851668516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169363 (or 169361 counting only the distinct ones).

The product of its digits is 16934400, while the sum is 60.

The spelling of 77851668516 in words is "seventy-seven billion, eight hundred fifty-one million, six hundred sixty-eight thousand, five hundred sixteen".