645560420 has 24 divisors (see below), whose sum is σ = 1358840448. Its totient is φ = 257621600.

The previous prime is 645560401. The next prime is 645560441. The reversal of 645560420 is 24065546.

645560420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28826 + ... + 46065.

It is an arithmetic number, because the mean of its divisors is an integer number (56618352).

Almost surely, 2^645560420 is an apocalyptic number.

It is an amenable number.

645560420 is an abundant number, since it is smaller than the sum of its proper divisors (713280028).

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

645560420 is a wasteful number, since it uses less digits than its factorization.

645560420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75331 (or 75329 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

The square root of 645560420 is about 25407.8810608047. The cubic root of 645560420 is about 864.2624249289.

The spelling of 645560420 in words is "six hundred forty-five million, five hundred sixty thousand, four hundred twenty".