645019213 has 2 divisors, whose sum is σ = 645019214. Its totient is φ = 645019212.

The previous prime is 645019181. The next prime is 645019217. The reversal of 645019213 is 312910546.

645019213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 579942724 + 65076489 = 24082^2 + 8067^2 .

It is a cyclic number.

It is not a de Polignac number, because 645019213 - 2⁵ = 645019181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645019217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322509606 + 322509607.

It is an arithmetic number, because the mean of its divisors is an integer number (322509607).

Almost surely, 2^645019213 is an apocalyptic number.

It is an amenable number.

645019213 is a deficient number, since it is larger than the sum of its proper divisors (1).

645019213 is an equidigital number, since it uses as much as digits as its factorization.

645019213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 645019213 is about 25397.2284511519. The cubic root of 645019213 is about 864.0208386356.

Adding to 645019213 its reverse (312910546), we get a palindrome (957929759).

The spelling of 645019213 in words is "six hundred forty-five million, nineteen thousand, two hundred thirteen".