8128423379521 has 9 divisors (see below), whose sum is σ = 8399180208483. Its totient is φ = 7866130642560.

The previous prime is 8128423379477. The next prime is 8128423379539. The reversal of 8128423379521 is 1259733248218.

It is a happy number.

The square root of 8128423379521 is 2851039.

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

It can be written as a sum of positive squares in only one way, i.e., 5250921837121 + 2877501542400 = 2291489^2 + 1696320^2 .

It is not a de Polignac number, because 8128423379521 - 2⁹ = 8128423379009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8128423379581) 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, 88336225 + ... + 88428193.

It is an arithmetic number, because the mean of its divisors is an integer number (933242245387).

Almost surely, 2^{8128423379521} is an apocalyptic number.

8128423379521 is the 2851039-th square number.

8128423379521 is the 1425520-th centered octagonal number.

It is an amenable number.

8128423379521 is a deficient number, since it is larger than the sum of its proper divisors (270756828962).

8128423379521 is an frugal number, since it uses more digits than its factorization.

8128423379521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184000 (or 92000 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 55.

The spelling of 8128423379521 in words is "eight trillion, one hundred twenty-eight billion, four hundred twenty-three million, three hundred seventy-nine thousand, five hundred twenty-one".