645345 has 12 divisors (see below), whose sum is σ = 1118676. Its totient is φ = 344160.

The previous prime is 645329. The next prime is 645347. The reversal of 645345 is 543546.

645345 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 91809 + 553536 = 303^2 + 744^2 .

It is not a de Polignac number, because 645345 - 2⁴ = 645329 is a prime.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (645347) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7126 + ... + 7215.

It is an arithmetic number, because the mean of its divisors is an integer number (93223).

2⁶⁴⁵³⁴⁵ is an apocalyptic number.

It is an amenable number.

645345 is a deficient number, since it is larger than the sum of its proper divisors (473331).

645345 is a wasteful number, since it uses less digits than its factorization.

645345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14352 (or 14349 counting only the distinct ones).

The product of its digits is 7200, while the sum is 27.

The square root of 645345 is about 803.3336791147. Note that the first 3 decimals coincide. The cubic root of 645345 is about 86.4166281011.

It can be divided in two parts, 645 and 345, that added together give a triangular number (990 = T₄₄).

The spelling of 645345 in words is "six hundred forty-five thousand, three hundred forty-five".