645041 has 2 divisors, whose sum is σ = 645042. Its totient is φ = 645040.

The previous prime is 645037. The next prime is 645049. The reversal of 645041 is 140546.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640000 + 5041 = 800^2 + 71^2 .

It is a cyclic number.

It is not a de Polignac number, because 645041 - 2² = 645037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (645049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322520 + 322521.

It is an arithmetic number, because the mean of its divisors is an integer number (322521).

2⁶⁴⁵⁰⁴¹ is an apocalyptic number.

It is an amenable number.

645041 is a deficient number, since it is larger than the sum of its proper divisors (1).

645041 is an equidigital number, since it uses as much as digits as its factorization.

645041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 645041 is about 803.1444452899. The cubic root of 645041 is about 86.4030566620.

Adding to 645041 its reverse (140546), we get a palindrome (785587).

It can be divided in two parts, 64 and 5041, that multiplied together give a square (322624 = 568²).

The spelling of 645041 in words is "six hundred forty-five thousand, forty-one".