647651 has 2 divisors, whose sum is σ = 647652. Its totient is φ = 647650.

The previous prime is 647641. The next prime is 647659. The reversal of 647651 is 156746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647651 - 2⁶ = 647587 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647651.

It is not a weakly prime, because it can be changed into another prime (647659) 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, 323825 + 323826.

It is an arithmetic number, because the mean of its divisors is an integer number (323826).

2⁶⁴⁷⁶⁵¹ is an apocalyptic number.

647651 is a deficient number, since it is larger than the sum of its proper divisors (1).

647651 is an equidigital number, since it uses as much as digits as its factorization.

647651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 29.

The square root of 647651 is about 804.7676683366. The cubic root of 647651 is about 86.5194360860.

The spelling of 647651 in words is "six hundred forty-seven thousand, six hundred fifty-one".