644602247 has 2 divisors, whose sum is σ = 644602248. Its totient is φ = 644602246.

The previous prime is 644602241. The next prime is 644602289. The reversal of 644602247 is 742206446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644602247 - 2¹² = 644598151 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644602241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322301123 + 322301124.

It is an arithmetic number, because the mean of its divisors is an integer number (322301124).

Almost surely, 2^644602247 is an apocalyptic number.

644602247 is a deficient number, since it is larger than the sum of its proper divisors (1).

644602247 is an equidigital number, since it uses as much as digits as its factorization.

644602247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 35.

The square root of 644602247 is about 25389.0182362375. The cubic root of 644602247 is about 863.8346193913.

The spelling of 644602247 in words is "six hundred forty-four million, six hundred two thousand, two hundred forty-seven".