665846513 has 2 divisors, whose sum is σ = 665846514. Its totient is φ = 665846512.

The previous prime is 665846479. The next prime is 665846521. The reversal of 665846513 is 315648566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631366129 + 34480384 = 25127^2 + 5872^2 .

It is a cyclic number.

It is not a de Polignac number, because 665846513 - 2²⁴ = 649069297 is a prime.

It is not a weakly prime, because it can be changed into another prime (665846543) 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, 332923256 + 332923257.

It is an arithmetic number, because the mean of its divisors is an integer number (332923257).

Almost surely, 2^665846513 is an apocalyptic number.

It is an amenable number.

665846513 is a deficient number, since it is larger than the sum of its proper divisors (1).

665846513 is an equidigital number, since it uses as much as digits as its factorization.

665846513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 518400, while the sum is 44.

The square root of 665846513 is about 25804.0018795535. The cubic root of 665846513 is about 873.2220826213. Note that the first 3 decimals are identical.

The spelling of 665846513 in words is "six hundred sixty-five million, eight hundred forty-six thousand, five hundred thirteen".