643224013 has 2 divisors, whose sum is σ = 643224014. Its totient is φ = 643224012.

The previous prime is 643224011. The next prime is 643224061. The reversal of 643224013 is 310422346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 469458889 + 173765124 = 21667^2 + 13182^2 .

It is a cyclic number.

It is not a de Polignac number, because 643224013 - 2¹ = 643224011 is a prime.

Together with 643224011, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643224011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321612006 + 321612007.

It is an arithmetic number, because the mean of its divisors is an integer number (321612007).

Almost surely, 2^643224013 is an apocalyptic number.

It is an amenable number.

643224013 is a deficient number, since it is larger than the sum of its proper divisors (1).

643224013 is an equidigital number, since it uses as much as digits as its factorization.

643224013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 643224013 is about 25361.8613867358. The cubic root of 643224013 is about 863.2185207142.

Adding to 643224013 its reverse (310422346), we get a palindrome (953646359).

The spelling of 643224013 in words is "six hundred forty-three million, two hundred twenty-four thousand, thirteen".