645807 has 8 divisors (see below), whose sum is σ = 875440. Its totient is φ = 423360.

The previous prime is 645803. The next prime is 645833. The reversal of 645807 is 708546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645807 - 2² = 645803 is a prime.

It is a Duffinian number.

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 645807.

It is not an unprimeable number, because it can be changed into a prime (645803) 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 7 ways as a sum of consecutive naturals, for example, 1582 + ... + 1947.

It is an arithmetic number, because the mean of its divisors is an integer number (109430).

2⁶⁴⁵⁸⁰⁷ is an apocalyptic number.

645807 is a deficient number, since it is larger than the sum of its proper divisors (229633).

645807 is a wasteful number, since it uses less digits than its factorization.

645807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3593.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 645807 is about 803.6211794123. The cubic root of 645807 is about 86.4372449591.

The spelling of 645807 in words is "six hundred forty-five thousand, eight hundred seven".