665489923 has 6 divisors (see below), whose sum is σ = 774141396. Its totient is φ = 570419892.

The previous prime is 665489921. The next prime is 665489947. The reversal of 665489923 is 329984566.

It is not a de Polignac number, because 665489923 - 2¹ = 665489921 is a prime.

It is a super-2 number, since 2×665489923² = 885753675229091858, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (665489921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6790665 + ... + 6790762.

It is an arithmetic number, because the mean of its divisors is an integer number (129023566).

Almost surely, 2^665489923 is an apocalyptic number.

665489923 is a deficient number, since it is larger than the sum of its proper divisors (108651473).

665489923 is a wasteful number, since it uses less digits than its factorization.

665489923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13581441 (or 13581434 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 52.

The square root of 665489923 is about 25797.0913670514. The cubic root of 665489923 is about 873.0661718825.

The spelling of 665489923 in words is "six hundred sixty-five million, four hundred eighty-nine thousand, nine hundred twenty-three".