645131255564 has 12 divisors (see below), whose sum is σ = 1132124490000. Its totient is φ = 321667115568.

The previous prime is 645131255551. The next prime is 645131255611. The reversal of 645131255564 is 465552131546.

It is a happy number.

645131255564 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 3 ways as a sum of consecutive naturals, for example, 224626439 + ... + 224629310.

It is an arithmetic number, because the mean of its divisors is an integer number (94343707500).

Almost surely, 2^645131255564 is an apocalyptic number.

It is an amenable number.

645131255564 is a deficient number, since it is larger than the sum of its proper divisors (486993234436).

645131255564 is a wasteful number, since it uses less digits than its factorization.

645131255564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449256112 (or 449256110 counting only the distinct ones).

The product of its digits is 2160000, while the sum is 47.

The spelling of 645131255564 in words is "six hundred forty-five billion, one hundred thirty-one million, two hundred fifty-five thousand, five hundred sixty-four".