665549063 has 4 divisors (see below), whose sum is σ = 665698440. Its totient is φ = 665399688.

The previous prime is 665549041. The next prime is 665549077. The reversal of 665549063 is 360945566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 360945566 = 2 ⋅180472783.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665549063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665549083) 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 in 3 ways as a sum of consecutive naturals, for example, 67793 + ... + 76986.

It is an arithmetic number, because the mean of its divisors is an integer number (166424610).

Almost surely, 2^665549063 is an apocalyptic number.

665549063 is a deficient number, since it is larger than the sum of its proper divisors (149377).

665549063 is a wasteful number, since it uses less digits than its factorization.

665549063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149376.

The product of its (nonzero) digits is 583200, while the sum is 44.

The square root of 665549063 is about 25798.2375948436. The cubic root of 665549063 is about 873.0920333329.

The spelling of 665549063 in words is "six hundred sixty-five million, five hundred forty-nine thousand, sixty-three".