665610775 has 12 divisors (see below), whose sum is σ = 873908352. Its totient is φ = 501165440.

The previous prime is 665610773. The next prime is 665610811. The reversal of 665610775 is 577016566.

It is not a de Polignac number, because 665610775 - 2¹ = 665610773 is a prime.

It is a super-2 number, since 2×665610775² = 886075407592201250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665610773) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 782647 + ... + 783496.

It is an arithmetic number, because the mean of its divisors is an integer number (72825696).

Almost surely, 2^665610775 is an apocalyptic number.

665610775 is a deficient number, since it is larger than the sum of its proper divisors (208297577).

665610775 is a wasteful number, since it uses less digits than its factorization.

665610775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566170 (or 1566165 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 43.

The square root of 665610775 is about 25799.4336178142. The cubic root of 665610775 is about 873.1190178651.

The spelling of 665610775 in words is "six hundred sixty-five million, six hundred ten thousand, seven hundred seventy-five".