665499409 has 8 divisors (see below), whose sum is σ = 686884320. Its totient is φ = 644451456.

The previous prime is 665499389. The next prime is 665499421. The reversal of 665499409 is 904994566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665499409 - 2¹⁷ = 665368337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665499469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80224 + ... + 88129.

It is an arithmetic number, because the mean of its divisors is an integer number (85860540).

Almost surely, 2^665499409 is an apocalyptic number.

It is an amenable number.

665499409 is a deficient number, since it is larger than the sum of its proper divisors (21384911).

665499409 is a wasteful number, since it uses less digits than its factorization.

665499409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168479.

The product of its (nonzero) digits is 2099520, while the sum is 52.

The square root of 665499409 is about 25797.2752243333. The cubic root of 665499409 is about 873.0703201378.

The spelling of 665499409 in words is "six hundred sixty-five million, four hundred ninety-nine thousand, four hundred nine".