665964577 has 2 divisors, whose sum is σ = 665964578. Its totient is φ = 665964576.

The previous prime is 665964553. The next prime is 665964581. The reversal of 665964577 is 775469566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 653262481 + 12702096 = 25559^2 + 3564^2 .

It is a cyclic number.

It is not a de Polignac number, because 665964577 - 2¹¹ = 665962529 is a prime.

It is not a weakly prime, because it can be changed into another prime (665964547) 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, 332982288 + 332982289.

It is an arithmetic number, because the mean of its divisors is an integer number (332982289).

Almost surely, 2^665964577 is an apocalyptic number.

It is an amenable number.

665964577 is a deficient number, since it is larger than the sum of its proper divisors (1).

665964577 is an equidigital number, since it uses as much as digits as its factorization.

665964577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9525600, while the sum is 55.

The square root of 665964577 is about 25806.2894853173. The cubic root of 665964577 is about 873.2736911111.

The spelling of 665964577 in words is "six hundred sixty-five million, nine hundred sixty-four thousand, five hundred seventy-seven".