7666613388225 has 243 divisors, whose sum is σ = 15339456056379. Its totient is φ = 3657559910400.

The previous prime is 7666613388223. The next prime is 7666613388233. The reversal of 7666613388225 is 5228833166667.

The square root of 7666613388225 is 2768865.

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

It can be written as a sum of positive squares in 13 ways, for example, as 1750860886401 + 5915752501824 = 1323201^2 + 2432232^2 .

It is not a de Polignac number, because 7666613388225 - 2¹ = 7666613388223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7666613388223) 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 242 ways as a sum of consecutive naturals, for example, 44315684239 + ... + 44315684411.

Almost surely, 2^{7666613388225} is an apocalyptic number.

7666613388225 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

7666613388225 is the 2768865-th square number.

7666613388225 is the 1384433-rd centered octagonal number.

It is an amenable number.

7666613388225 is an abundant number, since it is smaller than the sum of its proper divisors (7672842668154).

7666613388225 is a wasteful number, since it uses less digits than its factorization.

7666613388225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578 (or 289 counting only the distinct ones).

The product of its digits is 104509440, while the sum is 63.

The spelling of 7666613388225 in words is "seven trillion, six hundred sixty-six billion, six hundred thirteen million, three hundred eighty-eight thousand, two hundred twenty-five".