645593 has 8 divisors (see below), whose sum is σ = 709128. Its totient is φ = 584064.

The previous prime is 645583. The next prime is 645599. The reversal of 645593 is 395546.

It is a happy number.

645593 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in 4 ways, for example, as 784 + 644809 = 28^2 + 803^2 .

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

It is not a de Polignac number, because 645593 - 2⁴ = 645577 is a prime.

It is a Duffinian number.

645593 is an undulating number in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645593.

It is not an unprimeable number, because it can be changed into a prime (645599) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 221 + ... + 1157.

It is an arithmetic number, because the mean of its divisors is an integer number (88641).

2⁶⁴⁵⁵⁹³ is an apocalyptic number.

It is an amenable number.

645593 is a deficient number, since it is larger than the sum of its proper divisors (63535).

645593 is a wasteful number, since it uses less digits than its factorization.

645593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1003.

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

The square root of 645593 is about 803.4880210681. The cubic root of 645593 is about 86.4276963819.

Subtracting from 645593 its reverse (395546), we obtain a cube (250047 = 63³).

The spelling of 645593 in words is "six hundred forty-five thousand, five hundred ninety-three".