665605693 has 2 divisors, whose sum is σ = 665605694. Its totient is φ = 665605692.

The previous prime is 665605639. The next prime is 665605753. The reversal of 665605693 is 396506566.

Together with previous prime (665605639) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 531671364 + 133934329 = 23058^2 + 11573^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665605693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665600693) 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, 332802846 + 332802847.

It is an arithmetic number, because the mean of its divisors is an integer number (332802847).

Almost surely, 2^665605693 is an apocalyptic number.

It is an amenable number.

665605693 is a deficient number, since it is larger than the sum of its proper divisors (1).

665605693 is an equidigital number, since it uses as much as digits as its factorization.

665605693 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 874800, while the sum is 46.

The square root of 665605693 is about 25799.3351270919. The cubic root of 665605693 is about 873.1167957445.

The spelling of 665605693 in words is "six hundred sixty-five million, six hundred five thousand, six hundred ninety-three".