646255019 has 2 divisors, whose sum is σ = 646255020. Its totient is φ = 646255018.

The previous prime is 646255013. The next prime is 646255021. The reversal of 646255019 is 910552646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646255019 - 2²⁴ = 629477803 is a prime.

It is a super-2 number, since 2×646255019² = 835291099165380722, which contains 22 as substring.

Together with 646255021, 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 (646255013) 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, 323127509 + 323127510.

It is an arithmetic number, because the mean of its divisors is an integer number (323127510).

Almost surely, 2^646255019 is an apocalyptic number.

646255019 is a deficient number, since it is larger than the sum of its proper divisors (1).

646255019 is an equidigital number, since it uses as much as digits as its factorization.

646255019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64800, while the sum is 38.

The square root of 646255019 is about 25421.5463534381. The cubic root of 646255019 is about 864.5722852302.

The spelling of 646255019 in words is "six hundred forty-six million, two hundred fifty-five thousand, nineteen".