646021241 has 2 divisors, whose sum is σ = 646021242. Its totient is φ = 646021240.

The previous prime is 646021231. The next prime is 646021279. The reversal of 646021241 is 142120646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 475065616 + 170955625 = 21796^2 + 13075^2 .

It is a cyclic number.

It is not a de Polignac number, because 646021241 - 2¹⁴ = 646004857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646021241.

It is not a weakly prime, because it can be changed into another prime (646021231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323010620 + 323010621.

It is an arithmetic number, because the mean of its divisors is an integer number (323010621).

Almost surely, 2^646021241 is an apocalyptic number.

It is an amenable number.

646021241 is a deficient number, since it is larger than the sum of its proper divisors (1).

646021241 is an equidigital number, since it uses as much as digits as its factorization.

646021241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 646021241 is about 25416.9479088265. The cubic root of 646021241 is about 864.4680217686.

Adding to 646021241 its reverse (142120646), we get a palindrome (788141887).

The spelling of 646021241 in words is "six hundred forty-six million, twenty-one thousand, two hundred forty-one".