665525519 has 2 divisors, whose sum is σ = 665525520. Its totient is φ = 665525518.

The previous prime is 665525501. The next prime is 665525569. The reversal of 665525519 is 915525566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665525519 is a prime.

It is a super-2 number, since 2×665525519² = 885848432880438722, 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 665525519.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665525569) 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, 332762759 + 332762760.

It is an arithmetic number, because the mean of its divisors is an integer number (332762760).

Almost surely, 2^665525519 is an apocalyptic number.

665525519 is a deficient number, since it is larger than the sum of its proper divisors (1).

665525519 is an equidigital number, since it uses as much as digits as its factorization.

665525519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 405000, while the sum is 44.

The square root of 665525519 is about 25797.7812805675. The cubic root of 665525519 is about 873.0817379130.

The spelling of 665525519 in words is "six hundred sixty-five million, five hundred twenty-five thousand, five hundred nineteen".