77986656 has 144 divisors (see below), whose sum is σ = 245306880. Its totient is φ = 23304960.

The previous prime is 77986651. The next prime is 77986663. The reversal of 77986656 is 65668977.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77986651) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 326185 + ... + 326423.

It is an arithmetic number, because the mean of its divisors is an integer number (1703520).

Almost surely, 2^77986656 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 77986656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122653440).

77986656 is an abundant number, since it is smaller than the sum of its proper divisors (167320224).

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

77986656 is a wasteful number, since it uses less digits than its factorization.

77986656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369 (or 358 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 54.

The square root of 77986656 is about 8831.0053787777. The cubic root of 77986656 is about 427.2415016702.

The spelling of 77986656 in words is "seventy-seven million, nine hundred eighty-six thousand, six hundred fifty-six".