8991780625 has 15 divisors (see below), whose sum is σ = 11239092183. Its totient is φ = 7191528000.

The previous prime is 8991780617. The next prime is 8991780649. The reversal of 8991780625 is 5260871998.

The square root of 8991780625 is 94825.

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

It can be written as a sum of positive squares in 7 ways, for example, as 8774630929 + 217149696 = 93673^2 + 14736^2 .

It is not a de Polignac number, because 8991780625 - 2³ = 8991780617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 14 ways as a sum of consecutive naturals, for example, 2368729 + ... + 2372521.

Almost surely, 2^8991780625 is an apocalyptic number.

8991780625 is the 94825-th square number.

8991780625 is the 47413-rd centered octagonal number.

It is an amenable number.

8991780625 is a deficient number, since it is larger than the sum of its proper divisors (2247311558).

8991780625 is an frugal number, since it uses more digits than its factorization.

8991780625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7606 (or 3798 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 55.

The cubic root of 8991780625 is about 2079.4504083740.

The spelling of 8991780625 in words is "eight billion, nine hundred ninety-one million, seven hundred eighty thousand, six hundred twenty-five".