77908758256 has 80 divisors (see below), whose sum is σ = 176813058240. Its totient is φ = 32557916160.

The previous prime is 77908758251. The next prime is 77908758313. The reversal of 77908758256 is 65285780977.

It is a happy number.

It is a super-2 number, since 2×77908758256² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77908758251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12528460 + ... + 12534676.

It is an arithmetic number, because the mean of its divisors is an integer number (2210163228).

Almost surely, 2^77908758256 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 77908758256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88406529120).

77908758256 is an abundant number, since it is smaller than the sum of its proper divisors (98904299984).

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

77908758256 is a wasteful number, since it uses less digits than its factorization.

77908758256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9002 (or 8996 counting only the distinct ones).

The product of its (nonzero) digits is 59270400, while the sum is 64.

The spelling of 77908758256 in words is "seventy-seven billion, nine hundred eight million, seven hundred fifty-eight thousand, two hundred fifty-six".