643520453 has 2 divisors, whose sum is σ = 643520454. Its totient is φ = 643520452.

The previous prime is 643520441. The next prime is 643520509. The reversal of 643520453 is 354025346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 324612289 + 318908164 = 18017^2 + 17858^2 .

It is a cyclic number.

It is not a de Polignac number, because 643520453 - 2²⁰ = 642471877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643520153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321760226 + 321760227.

It is an arithmetic number, because the mean of its divisors is an integer number (321760227).

Almost surely, 2^643520453 is an apocalyptic number.

It is an amenable number.

643520453 is a deficient number, since it is larger than the sum of its proper divisors (1).

643520453 is an equidigital number, since it uses as much as digits as its factorization.

643520453 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 32.

The square root of 643520453 is about 25367.7049218095. The cubic root of 643520453 is about 863.3511096684.

Adding to 643520453 its reverse (354025346), we get a palindrome (997545799).

The spelling of 643520453 in words is "six hundred forty-three million, five hundred twenty thousand, four hundred fifty-three".