645535 has 16 divisors (see below), whose sum is σ = 860832. Its totient is φ = 464640.

The previous prime is 645529. The next prime is 645571. The reversal of 645535 is 535546.

It is not a de Polignac number, because 645535 - 2³ = 645527 is a prime.

It is a Duffinian number.

645535 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6607 + ... + 6703.

It is an arithmetic number, because the mean of its divisors is an integer number (53802).

2⁶⁴⁵⁵³⁵ is an apocalyptic number.

645535 is a deficient number, since it is larger than the sum of its proper divisors (215297).

645535 is an equidigital number, since it uses as much as digits as its factorization.

645535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 113 counting only the distinct ones).

The product of its digits is 9000, while the sum is 28.

The square root of 645535 is about 803.4519276223. The cubic root of 645535 is about 86.4251080863.

The spelling of 645535 in words is "six hundred forty-five thousand, five hundred thirty-five".