645599 has 2 divisors, whose sum is σ = 645600. Its totient is φ = 645598.

The previous prime is 645583. The next prime is 645611. The reversal of 645599 is 995546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645599 - 2⁴ = 645583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322799 + 322800.

It is an arithmetic number, because the mean of its divisors is an integer number (322800).

2⁶⁴⁵⁵⁹⁹ is an apocalyptic number.

645599 is a deficient number, since it is larger than the sum of its proper divisors (1).

645599 is an equidigital number, since it uses as much as digits as its factorization.

645599 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48600, while the sum is 38.

The square root of 645599 is about 803.4917547803. The cubic root of 645599 is about 86.4279641278.

The spelling of 645599 in words is "six hundred forty-five thousand, five hundred ninety-nine".