6645825220 has 12 divisors (see below), whose sum is σ = 13956233004. Its totient is φ = 2658330080.

The previous prime is 6645825211. The next prime is 6645825227. The reversal of 6645825220 is 225285466.

It can be written as a sum of positive squares in 2 ways, for example, as 2651838016 + 3993987204 = 51496^2 + 63198^2 .

It is not an unprimeable number, because it can be changed into a prime (6645825227) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 166145611 + ... + 166145650.

It is an arithmetic number, because the mean of its divisors is an integer number (1163019417).

Almost surely, 2^6645825220 is an apocalyptic number.

It is an amenable number.

6645825220 is an abundant number, since it is smaller than the sum of its proper divisors (7310407784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6645825220 is a wasteful number, since it uses less digits than its factorization.

6645825220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332291270 (or 332291268 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 40.

The square root of 6645825220 is about 81521.9309143251. The cubic root of 6645825220 is about 1880.1087552145.

The spelling of 6645825220 in words is "six billion, six hundred forty-five million, eight hundred twenty-five thousand, two hundred twenty".