643498337 has 2 divisors, whose sum is σ = 643498338. Its totient is φ = 643498336.

The previous prime is 643498319. The next prime is 643498357. The reversal of 643498337 is 733894346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 641304976 + 2193361 = 25324^2 + 1481^2 .

It is a cyclic number.

It is not a de Polignac number, because 643498337 - 2¹⁴ = 643481953 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643498291 and 643498300.

It is not a weakly prime, because it can be changed into another prime (643498307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321749168 + 321749169.

It is an arithmetic number, because the mean of its divisors is an integer number (321749169).

Almost surely, 2^643498337 is an apocalyptic number.

It is an amenable number.

643498337 is a deficient number, since it is larger than the sum of its proper divisors (1).

643498337 is an equidigital number, since it uses as much as digits as its factorization.

643498337 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 47.

The square root of 643498337 is about 25367.2690094933. The cubic root of 643498337 is about 863.3412192333.

The spelling of 643498337 in words is "six hundred forty-three million, four hundred ninety-eight thousand, three hundred thirty-seven".