646320247 has 2 divisors, whose sum is σ = 646320248. Its totient is φ = 646320246.

The previous prime is 646320239. The next prime is 646320281. The reversal of 646320247 is 742023646.

It is an a-pointer prime, because the next prime (646320281) can be obtained adding 646320247 to its sum of digits (34).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646320247 - 2³ = 646320239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646320287) 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, 323160123 + 323160124.

It is an arithmetic number, because the mean of its divisors is an integer number (323160124).

Almost surely, 2^646320247 is an apocalyptic number.

646320247 is a deficient number, since it is larger than the sum of its proper divisors (1).

646320247 is an equidigital number, since it uses as much as digits as its factorization.

646320247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 646320247 is about 25422.8292485317. The cubic root of 646320247 is about 864.6013720056.

The spelling of 646320247 in words is "six hundred forty-six million, three hundred twenty thousand, two hundred forty-seven".