77686727508 has 384 divisors, whose sum is σ = 242149376000. Its totient is φ = 21314327040.

The previous prime is 77686727507. The next prime is 77686727509. The reversal of 77686727508 is 80572768677.

77686727508 is a `hidden beast` number, since 7 + 7 + 68 + 67 + 2 + 7 + 508 = 666.

It is an interprime number because it is at equal distance from previous prime (77686727507) and next prime (77686727509).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77686727501) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 30596103 + ... + 30598641.

Almost surely, 2^77686727508 is an apocalyptic number.

77686727508 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77686727508, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121074688000).

77686727508 is an abundant number, since it is smaller than the sum of its proper divisors (164462648492).

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

77686727508 is a wasteful number, since it uses less digits than its factorization.

77686727508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2652 (or 2644 counting only the distinct ones).

The product of its (nonzero) digits is 55319040, while the sum is 63.

The spelling of 77686727508 in words is "seventy-seven billion, six hundred eighty-six million, seven hundred twenty-seven thousand, five hundred eight".