645935 has 4 divisors (see below), whose sum is σ = 775128. Its totient is φ = 516744.

The previous prime is 645907. The next prime is 645937. The reversal of 645935 is 539546.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645935 - 2¹⁰ = 644911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645937) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 64589 + ... + 64598.

It is an arithmetic number, because the mean of its divisors is an integer number (193782).

2⁶⁴⁵⁹³⁵ is an apocalyptic number.

645935 is a deficient number, since it is larger than the sum of its proper divisors (129193).

645935 is a wasteful number, since it uses less digits than its factorization.

645935 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129192.

The product of its digits is 16200, while the sum is 32.

The square root of 645935 is about 803.7008149803. The cubic root of 645935 is about 86.4429552495.

The spelling of 645935 in words is "six hundred forty-five thousand, nine hundred thirty-five".