665408997 has 12 divisors (see below), whose sum is σ = 1048523424. Its totient is φ = 403278120.

The previous prime is 665408981. The next prime is 665409001. The reversal of 665408997 is 799804566.

665408997 is a `hidden beast` number, since 6 + 6 + 540 + 8 + 9 + 97 = 666.

It is not a de Polignac number, because 665408997 - 2⁴ = 665408981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665408927) 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 11 ways as a sum of consecutive naturals, for example, 3360553 + ... + 3360750.

It is an arithmetic number, because the mean of its divisors is an integer number (87376952).

Almost surely, 2^665408997 is an apocalyptic number.

It is an amenable number.

665408997 is a deficient number, since it is larger than the sum of its proper divisors (383114427).

665408997 is a wasteful number, since it uses less digits than its factorization.

665408997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6721320 (or 6721317 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The square root of 665408997 is about 25795.5228092008. The cubic root of 665408997 is about 873.0307811051.

The spelling of 665408997 in words is "six hundred sixty-five million, four hundred eight thousand, nine hundred ninety-seven".