646444247 has 2 divisors, whose sum is σ = 646444248. Its totient is φ = 646444246.

The previous prime is 646444223. The next prime is 646444301. The reversal of 646444247 is 742444646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646444247 - 2²⁸ = 378008791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646404247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323222123 + 323222124.

It is an arithmetic number, because the mean of its divisors is an integer number (323222124).

Almost surely, 2^646444247 is an apocalyptic number.

646444247 is a deficient number, since it is larger than the sum of its proper divisors (1).

646444247 is an equidigital number, since it uses as much as digits as its factorization.

646444247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 516096, while the sum is 41.

The square root of 646444247 is about 25425.2678845278. The cubic root of 646444247 is about 864.6566612708.

The spelling of 646444247 in words is "six hundred forty-six million, four hundred forty-four thousand, two hundred forty-seven".