77217844320 has 240 divisors, whose sum is σ = 272752891488. Its totient is φ = 20573429760.

The previous prime is 77217844307. The next prime is 77217844339. The reversal of 77217844320 is 2344871277.

77217844320 is a `hidden beast` number, since 77 + 217 + 8 + 44 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 21991365 + ... + 21994875.

Almost surely, 2^77217844320 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 77217844320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136376445744).

77217844320 is an abundant number, since it is smaller than the sum of its proper divisors (195535047168).

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

77217844320 is a wasteful number, since it uses less digits than its factorization.

77217844320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5235 (or 5218 counting only the distinct ones).

The product of its (nonzero) digits is 526848, while the sum is 45.

The spelling of 77217844320 in words is "seventy-seven billion, two hundred seventeen million, eight hundred forty-four thousand, three hundred twenty".