77701661856 has 960 divisors, whose sum is σ = 295720685568. Its totient is φ = 19470108672.

The previous prime is 77701661833. The next prime is 77701661861. The reversal of 77701661856 is 65816610777.

77701661856 is a `hidden beast` number, since 7 + 7 + 7 + 0 + 16 + 618 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 159 ways as a sum of consecutive naturals, for example, 476697231 + ... + 476697393.

Almost surely, 2^77701661856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77701661856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147860342784).

77701661856 is an abundant number, since it is smaller than the sum of its proper divisors (218019023712).

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

77701661856 is a wasteful number, since it uses less digits than its factorization.

77701661856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 2963520, while the sum is 54.

The spelling of 77701661856 in words is "seventy-seven billion, seven hundred one million, six hundred sixty-one thousand, eight hundred fifty-six".