665280019 has 2 divisors, whose sum is σ = 665280020. Its totient is φ = 665280018.

The previous prime is 665279999. The next prime is 665280043. The reversal of 665280019 is 910082566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665280019 - 2¹¹ = 665277971 is a prime.

It is a super-2 number, since 2×665280019² = 885195007361280722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 665280019.

It is not a weakly prime, because it can be changed into another prime (665280059) 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, 332640009 + 332640010.

It is an arithmetic number, because the mean of its divisors is an integer number (332640010).

Almost surely, 2^665280019 is an apocalyptic number.

665280019 is a deficient number, since it is larger than the sum of its proper divisors (1).

665280019 is an equidigital number, since it uses as much as digits as its factorization.

665280019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 665280019 is about 25793.0226805623. The cubic root of 665280019 is about 872.9743701655.

The spelling of 665280019 in words is "six hundred sixty-five million, two hundred eighty thousand, nineteen".