663857 has 2 divisors, whose sum is σ = 663858. Its totient is φ = 663856.

The previous prime is 663853. The next prime is 663869. The reversal of 663857 is 758366.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 564001 + 99856 = 751^2 + 316^2 .

It is a cyclic number.

It is not a de Polignac number, because 663857 - 2² = 663853 is a prime.

It is a super-2 number, since 2×663857² = 881412232898, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (663853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331928 + 331929.

It is an arithmetic number, because the mean of its divisors is an integer number (331929).

2⁶⁶³⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

663857 is a deficient number, since it is larger than the sum of its proper divisors (1).

663857 is an equidigital number, since it uses as much as digits as its factorization.

663857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 35.

The square root of 663857 is about 814.7742018498. The cubic root of 663857 is about 87.2351501671.

The spelling of 663857 in words is "six hundred sixty-three thousand, eight hundred fifty-seven".