7918720128 has 144 divisors (see below), whose sum is σ = 25047244950. Its totient is φ = 2399569920.

The previous prime is 7918720067. The next prime is 7918720133. The reversal of 7918720128 is 8210278197.

It can be written as a sum of positive squares in only one way, i.e., 7915305024 + 3415104 = 88968^2 + 1848^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×7918720128² (a number of 21 digits) contains 22 as substring.

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 17 ways as a sum of consecutive naturals, for example, 110988 + ... + 167796.

Almost surely, 2^7918720128 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 7918720128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12523622475).

7918720128 is an abundant number, since it is smaller than the sum of its proper divisors (17128524822).

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

7918720128 is a wasteful number, since it uses less digits than its factorization.

7918720128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56851 (or 56825 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 7918720128 is about 88987.1908085653. The cubic root of 7918720128 is about 1993.2036080224.

The spelling of 7918720128 in words is "seven billion, nine hundred eighteen million, seven hundred twenty thousand, one hundred twenty-eight".