646351243 has 2 divisors, whose sum is σ = 646351244. Its totient is φ = 646351242.

The previous prime is 646351229. The next prime is 646351247. The reversal of 646351243 is 342153646.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646351243 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 646351199 and 646351208.

It is not a weakly prime, because it can be changed into another prime (646351247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323175621 + 323175622.

It is an arithmetic number, because the mean of its divisors is an integer number (323175622).

Almost surely, 2^646351243 is an apocalyptic number.

646351243 is a deficient number, since it is larger than the sum of its proper divisors (1).

646351243 is an equidigital number, since it uses as much as digits as its factorization.

646351243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 34.

The square root of 646351243 is about 25423.4388507928. The cubic root of 646351243 is about 864.6151932013.

The spelling of 646351243 in words is "six hundred forty-six million, three hundred fifty-one thousand, two hundred forty-three".