646957 has 2 divisors, whose sum is σ = 646958. Its totient is φ = 646956.

The previous prime is 646937. The next prime is 646979. The reversal of 646957 is 759646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 443556 + 203401 = 666^2 + 451^2 .

It is a cyclic number.

It is not a de Polignac number, because 646957 - 2¹¹ = 644909 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 (646927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323478 + 323479.

It is an arithmetic number, because the mean of its divisors is an integer number (323479).

2⁶⁴⁶⁹⁵⁷ is an apocalyptic number.

It is an amenable number.

646957 is a deficient number, since it is larger than the sum of its proper divisors (1).

646957 is an equidigital number, since it uses as much as digits as its factorization.

646957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 37.

The square root of 646957 is about 804.3363724214. The cubic root of 646957 is about 86.4885213142.

It can be divided in two parts, 64 and 6957, that added together give a triangular number (7021 = T₁₁₈).

The spelling of 646957 in words is "six hundred forty-six thousand, nine hundred fifty-seven".