6663645425 has 12 divisors (see below), whose sum is σ = 8486243676. Its totient is φ = 5186836800.

The previous prime is 6663645419. The next prime is 6663645481. The reversal of 6663645425 is 5245463666.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 19439281 + 6644206144 = 4409^2 + 81512^2 .

It is not a de Polignac number, because 6663645425 - 2⁶ = 6663645361 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6663645425.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3601046 + ... + 3602895.

It is an arithmetic number, because the mean of its divisors is an integer number (707186973).

Almost surely, 2^6663645425 is an apocalyptic number.

It is an amenable number.

6663645425 is a deficient number, since it is larger than the sum of its proper divisors (1822598251).

6663645425 is a wasteful number, since it uses less digits than its factorization.

6663645425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7203988 (or 7203983 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 47.

The square root of 6663645425 is about 81631.1547449869. The cubic root of 6663645425 is about 1881.7877050768.

The spelling of 6663645425 in words is "six billion, six hundred sixty-three million, six hundred forty-five thousand, four hundred twenty-five".