77908809312 has 288 divisors, whose sum is σ = 256086230400. Its totient is φ = 23154812928.

The previous prime is 77908809281. The next prime is 77908809313. The reversal of 77908809312 is 21390880977.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77908809313) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2496139 + ... + 2527157.

It is an arithmetic number, because the mean of its divisors is an integer number (889188300).

Almost surely, 2^77908809312 is an apocalyptic number.

77908809312 is a gapful number since it is divisible by the number (72) 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 77908809312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128043115200).

77908809312 is an abundant number, since it is smaller than the sum of its proper divisors (178177421088).

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

77908809312 is a wasteful number, since it uses less digits than its factorization.

77908809312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31080 (or 31060 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 77908809312 in words is "seventy-seven billion, nine hundred eight million, eight hundred nine thousand, three hundred twelve".