646446491 has 2 divisors, whose sum is σ = 646446492. Its totient is φ = 646446490.

The previous prime is 646446473. The next prime is 646446517. The reversal of 646446491 is 194644646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646446491 - 2¹⁴ = 646430107 is a prime.

It is not a weakly prime, because it can be changed into another prime (646446461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323223245 + 323223246.

It is an arithmetic number, because the mean of its divisors is an integer number (323223246).

Almost surely, 2^646446491 is an apocalyptic number.

646446491 is a deficient number, since it is larger than the sum of its proper divisors (1).

646446491 is an equidigital number, since it uses as much as digits as its factorization.

646446491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 497664, while the sum is 44.

The square root of 646446491 is about 25425.3120138180. The cubic root of 646446491 is about 864.6576617630.

The spelling of 646446491 in words is "six hundred forty-six million, four hundred forty-six thousand, four hundred ninety-one".