665016655 has 4 divisors (see below), whose sum is σ = 798019992. Its totient is φ = 532013320.

The previous prime is 665016647. The next prime is 665016673. The reversal of 665016655 is 556610566.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 665016655 - 2³ = 665016647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 66501661 + ... + 66501670.

It is an arithmetic number, because the mean of its divisors is an integer number (199504998).

Almost surely, 2^665016655 is an apocalyptic number.

665016655 is a deficient number, since it is larger than the sum of its proper divisors (133003337).

665016655 is a wasteful number, since it uses less digits than its factorization.

665016655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133003336.

The product of its (nonzero) digits is 162000, while the sum is 40.

The square root of 665016655 is about 25787.9168410324. The cubic root of 665016655 is about 872.8591603490.

The spelling of 665016655 in words is "six hundred sixty-five million, sixteen thousand, six hundred fifty-five".