665499407 has 4 divisors (see below), whose sum is σ = 665553096. Its totient is φ = 665445720.

The previous prime is 665499389. The next prime is 665499421. The reversal of 665499407 is 704994566.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 704994566 = 2 ⋅352497283.

It is a cyclic number.

It is not a de Polignac number, because 665499407 - 2⁸ = 665499151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665499487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2288 + ... + 36554.

It is an arithmetic number, because the mean of its divisors is an integer number (166388274).

Almost surely, 2^665499407 is an apocalyptic number.

665499407 is a deficient number, since it is larger than the sum of its proper divisors (53689).

665499407 is a wasteful number, since it uses less digits than its factorization.

665499407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53688.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The square root of 665499407 is about 25797.2751855695. The cubic root of 665499407 is about 873.0703192632.

The spelling of 665499407 in words is "six hundred sixty-five million, four hundred ninety-nine thousand, four hundred seven".