7128686401600 has 63 divisors (see below), whose sum is σ = 17541286771687. Its totient is φ = 2851431841280.

The previous prime is 7128686401549. The next prime is 7128686401609. The reversal of 7128686401600 is 61046868217.

The square root of 7128686401600 is 2669960.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 42719296 + 7128643682304 = 6536^2 + 2669952^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7128686401609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 106765026 + ... + 106831774.

Almost surely, 2^{7128686401600} is an apocalyptic number.

7128686401600 is the 2669960-th square number.

It is an amenable number.

7128686401600 is an abundant number, since it is smaller than the sum of its proper divisors (10412600370087).

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

7128686401600 is an frugal number, since it uses more digits than its factorization.

7128686401600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133520 (or 66756 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 49.

Multiplying 7128686401600 by its sum of digits (49), we get a square (349305633678400 = 18689720²).

The spelling of 7128686401600 in words is "seven trillion, one hundred twenty-eight billion, six hundred eighty-six million, four hundred one thousand, six hundred".