665216653 has 2 divisors, whose sum is σ = 665216654. Its totient is φ = 665216652.

The previous prime is 665216567. The next prime is 665216689. The reversal of 665216653 is 356612566.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 372567204 + 292649449 = 19302^2 + 17107^2 .

It is a cyclic number.

It is not a de Polignac number, because 665216653 - 2⁹ = 665216141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665211653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332608326 + 332608327.

It is an arithmetic number, because the mean of its divisors is an integer number (332608327).

Almost surely, 2^665216653 is an apocalyptic number.

It is an amenable number.

665216653 is a deficient number, since it is larger than the sum of its proper divisors (1).

665216653 is an equidigital number, since it uses as much as digits as its factorization.

665216653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 40.

The square root of 665216653 is about 25791.7942958608. The cubic root of 665216653 is about 872.9466531899.

The spelling of 665216653 in words is "six hundred sixty-five million, two hundred sixteen thousand, six hundred fifty-three".