647951 has 2 divisors, whose sum is σ = 647952. Its totient is φ = 647950.

The previous prime is 647917. The next prime is 647953. The reversal of 647951 is 159746.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647951 - 2¹⁰ = 646927 is a prime.

Together with 647953, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647953) 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, 323975 + 323976.

It is an arithmetic number, because the mean of its divisors is an integer number (323976).

2⁶⁴⁷⁹⁵¹ is an apocalyptic number.

647951 is a deficient number, since it is larger than the sum of its proper divisors (1).

647951 is an equidigital number, since it uses as much as digits as its factorization.

647951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 32.

The square root of 647951 is about 804.9540359548. The cubic root of 647951 is about 86.5327929836.

The spelling of 647951 in words is "six hundred forty-seven thousand, nine hundred fifty-one".