645583 has 2 divisors, whose sum is σ = 645584. Its totient is φ = 645582.

The previous prime is 645581. The next prime is 645599. The reversal of 645583 is 385546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645583 - 2¹ = 645581 is a prime.

Together with 645581, it forms a pair of twin primes.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645581) 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 as a sum of consecutive naturals, namely, 322791 + 322792.

It is an arithmetic number, because the mean of its divisors is an integer number (322792).

2⁶⁴⁵⁵⁸³ is an apocalyptic number.

645583 is a deficient number, since it is larger than the sum of its proper divisors (1).

645583 is an equidigital number, since it uses as much as digits as its factorization.

645583 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 31.

The square root of 645583 is about 803.4817981759. The cubic root of 645583 is about 86.4272501351.

The spelling of 645583 in words is "six hundred forty-five thousand, five hundred eighty-three".