646309841 has 2 divisors, whose sum is σ = 646309842. Its totient is φ = 646309840.

The previous prime is 646309813. The next prime is 646309843. The reversal of 646309841 is 148903646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 620259025 + 26050816 = 24905^2 + 5104^2 .

It is a cyclic number.

It is not a de Polignac number, because 646309841 - 2²⁶ = 579200977 is a prime.

Together with 646309843, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (646309843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323154920 + 323154921.

It is an arithmetic number, because the mean of its divisors is an integer number (323154921).

Almost surely, 2^646309841 is an apocalyptic number.

It is an amenable number.

646309841 is a deficient number, since it is larger than the sum of its proper divisors (1).

646309841 is an equidigital number, since it uses as much as digits as its factorization.

646309841 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 646309841 is about 25422.6245891332. The cubic root of 646309841 is about 864.5967318446.

The spelling of 646309841 in words is "six hundred forty-six million, three hundred nine thousand, eight hundred forty-one".