665881593 has 16 divisors (see below), whose sum is σ = 957116160. Its totient is φ = 409353984.

The previous prime is 665881589. The next prime is 665881597. The reversal of 665881593 is 395188566.

It is an interprime number because it is at equal distance from previous prime (665881589) and next prime (665881597).

It is not a de Polignac number, because 665881593 - 2² = 665881589 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665881597) 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 15 ways as a sum of consecutive naturals, for example, 32305 + ... + 48737.

It is an arithmetic number, because the mean of its divisors is an integer number (59819760).

Almost surely, 2^665881593 is an apocalyptic number.

It is an amenable number.

665881593 is a deficient number, since it is larger than the sum of its proper divisors (291234567).

665881593 is a wasteful number, since it uses less digits than its factorization.

665881593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17488.

The product of its digits is 1555200, while the sum is 51.

The square root of 665881593 is about 25804.6816101265. The cubic root of 665881593 is about 873.2374175331.

The spelling of 665881593 in words is "six hundred sixty-five million, eight hundred eighty-one thousand, five hundred ninety-three".