665355773 has 2 divisors, whose sum is σ = 665355774. Its totient is φ = 665355772.

The previous prime is 665355763. The next prime is 665355791. The reversal of 665355773 is 377553566.

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., 373185124 + 292170649 = 19318^2 + 17093^2 .

It is a cyclic number.

It is not a de Polignac number, because 665355773 - 2⁸ = 665355517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665355763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332677886 + 332677887.

It is an arithmetic number, because the mean of its divisors is an integer number (332677887).

Almost surely, 2^665355773 is an apocalyptic number.

It is an amenable number.

665355773 is a deficient number, since it is larger than the sum of its proper divisors (1).

665355773 is an equidigital number, since it uses as much as digits as its factorization.

665355773 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1984500, while the sum is 47.

The square root of 665355773 is about 25794.4911366749. The cubic root of 665355773 is about 873.0075034771.

It can be divided in two parts, 6653 and 55773, that added together give a palindrome (62426).

The spelling of 665355773 in words is "six hundred sixty-five million, three hundred fifty-five thousand, seven hundred seventy-three".