645056 has 14 divisors (see below), whose sum is σ = 1280160. Its totient is φ = 322496.

The previous prime is 645049. The next prime is 645067. The reversal of 645056 is 650546.

645056 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4976 + ... + 5103.

It is an arithmetic number, because the mean of its divisors is an integer number (91440).

2⁶⁴⁵⁰⁵⁶ is an apocalyptic number.

It is an amenable number.

645056 is a deficient number, since it is larger than the sum of its proper divisors (635104).

645056 is a wasteful number, since it uses less digits than its factorization.

645056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10091 (or 10081 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 645056 is about 803.1537835309. The cubic root of 645056 is about 86.4037264054.

The spelling of 645056 in words is "six hundred forty-five thousand, fifty-six".