645528 has 32 divisors (see below), whose sum is σ = 1738800. Its totient is φ = 198528.

The previous prime is 645527. The next prime is 645529. The reversal of 645528 is 825546.

645528 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645527) and next prime (645529).

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 645495 and 645504.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645528.

It is not an unprimeable number, because it can be changed into a prime (645521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 723 + ... + 1346.

2⁶⁴⁵⁵²⁸ is an apocalyptic number.

It is an amenable number.

645528 is an abundant number, since it is smaller than the sum of its proper divisors (1093272).

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

645528 is a wasteful number, since it uses less digits than its factorization.

645528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091 (or 2087 counting only the distinct ones).

The product of its digits is 9600, while the sum is 30.

The square root of 645528 is about 803.4475714071. The cubic root of 645528 is about 86.4247956953.

The spelling of 645528 in words is "six hundred forty-five thousand, five hundred twenty-eight".