645623020225 has 24 divisors (see below), whose sum is σ = 820218002688. Its totient is φ = 503973926400.

The previous prime is 645623020201. The next prime is 645623020241. The reversal of 645623020225 is 522020326546.

It is not a de Polignac number, because 645623020225 - 2⁵ = 645623020193 is a prime.

It is a Duffinian number.

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 23 ways as a sum of consecutive naturals, for example, 1702729 + ... + 2047078.

It is an arithmetic number, because the mean of its divisors is an integer number (34175750112).

Almost surely, 2^645623020225 is an apocalyptic number.

It is an amenable number.

645623020225 is a deficient number, since it is larger than the sum of its proper divisors (174594982463).

645623020225 is a wasteful number, since it uses less digits than its factorization.

645623020225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3749985 (or 3749980 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 37.

The spelling of 645623020225 in words is "six hundred forty-five billion, six hundred twenty-three million, twenty thousand, two hundred twenty-five".