9661278625 has 8 divisors (see below), whose sum is σ = 12057275880. Its totient is φ = 7729022800.

The previous prime is 9661278611. The next prime is 9661278629. The reversal of 9661278625 is 5268721669.

It can be written as a sum of positive squares in 4 ways, for example, as 2429306944 + 7231971681 = 49288^2 + 85041^2 .

It is not a de Polignac number, because 9661278625 - 2⁹ = 9661278113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9661278629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38644990 + ... + 38645239.

It is an arithmetic number, because the mean of its divisors is an integer number (1507159485).

Almost surely, 2^9661278625 is an apocalyptic number.

It is an amenable number.

9661278625 is a deficient number, since it is larger than the sum of its proper divisors (2395997255).

9661278625 is an equidigital number, since it uses as much as digits as its factorization.

9661278625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77290244 (or 77290234 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 52.

The square root of 9661278625 is about 98291.8034476934. The cubic root of 9661278625 is about 2129.8296516400.

The spelling of 9661278625 in words is "nine billion, six hundred sixty-one million, two hundred seventy-eight thousand, six hundred twenty-five".