665717057 has 2 divisors, whose sum is σ = 665717058. Its totient is φ = 665717056.

The previous prime is 665717029. The next prime is 665717077. The reversal of 665717057 is 750717566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 485056576 + 180660481 = 22024^2 + 13441^2 .

It is a cyclic number.

It is not a de Polignac number, because 665717057 - 2¹⁰ = 665716033 is a prime.

It is equal to p_34567793 and since 665717057 and 34567793 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 665716999 and 665717017.

It is not a weakly prime, because it can be changed into another prime (665717077) 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, 332858528 + 332858529.

It is an arithmetic number, because the mean of its divisors is an integer number (332858529).

Almost surely, 2^665717057 is an apocalyptic number.

It is an amenable number.

665717057 is a deficient number, since it is larger than the sum of its proper divisors (1).

665717057 is an equidigital number, since it uses as much as digits as its factorization.

665717057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 308700, while the sum is 44.

The square root of 665717057 is about 25801.4933094966. The cubic root of 665717057 is about 873.1654874137.

The spelling of 665717057 in words is "six hundred sixty-five million, seven hundred seventeen thousand, fifty-seven".