77728734720 has 960 divisors, whose sum is σ = 335027556864. Its totient is φ = 16217210880.

The previous prime is 77728734701. The next prime is 77728734737. The reversal of 77728734720 is 2743782777.

It is a tau number, because it is divible by the number of its divisors (960).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 274659699 + ... + 274659981.

Almost surely, 2^77728734720 is an apocalyptic number.

77728734720 is a gapful number since it is divisible by the number (70) 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 77728734720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167513778432).

77728734720 is an abundant number, since it is smaller than the sum of its proper divisors (257298822144).

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

77728734720 is a wasteful number, since it uses less digits than its factorization.

77728734720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463 (or 444 counting only the distinct ones).

The product of its (nonzero) digits is 6453888, while the sum is 54.

The spelling of 77728734720 in words is "seventy-seven billion, seven hundred twenty-eight million, seven hundred thirty-four thousand, seven hundred twenty".