647399 has 2 divisors, whose sum is σ = 647400. Its totient is φ = 647398.

The previous prime is 647371. The next prime is 647401. The reversal of 647399 is 993746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647399 - 2¹² = 643303 is a prime.

Together with 647401, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647399.

It is not a weakly prime, because it can be changed into another prime (647359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323699 + 323700.

It is an arithmetic number, because the mean of its divisors is an integer number (323700).

2⁶⁴⁷³⁹⁹ is an apocalyptic number.

647399 is a deficient number, since it is larger than the sum of its proper divisors (1).

647399 is an equidigital number, since it uses as much as digits as its factorization.

647399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 38.

The square root of 647399 is about 804.6110861777. The cubic root of 647399 is about 86.5082131041.

The spelling of 647399 in words is "six hundred forty-seven thousand, three hundred ninety-nine".