128720307456 has 648 divisors, whose sum is σ = 429471544320. Its totient is φ = 36954537984.

The previous prime is 128720307433. The next prime is 128720307511. The reversal of 128720307456 is 654703027821.

128720307456 is a `hidden beast` number, since 1 + 287 + 20 + 307 + 45 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 939564220 + ... + 939564356.

Almost surely, 2^128720307456 is an apocalyptic number.

128720307456 is a gapful number since it is divisible by the number (16) 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 128720307456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (214735772160).

128720307456 is an abundant number, since it is smaller than the sum of its proper divisors (300751236864).

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

128720307456 is a wasteful number, since it uses less digits than its factorization.

128720307456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331 (or 301 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 128720307456 in words is "one hundred twenty-eight billion, seven hundred twenty million, three hundred seven thousand, four hundred fifty-six".