665005805 has 16 divisors (see below), whose sum is σ = 810001920. Its totient is φ = 524040192.

The previous prime is 665005799. The next prime is 665005819. The reversal of 665005805 is 508500566.

It is a cyclic number.

It is not a de Polignac number, because 665005805 - 2⁶ = 665005741 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190637 + ... + 194093.

It is an arithmetic number, because the mean of its divisors is an integer number (50625120).

Almost surely, 2^665005805 is an apocalyptic number.

It is an amenable number.

665005805 is a deficient number, since it is larger than the sum of its proper divisors (144996115).

665005805 is a wasteful number, since it uses less digits than its factorization.

665005805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4028.

The product of its (nonzero) digits is 36000, while the sum is 35.

The square root of 665005805 is about 25787.7064703319. The cubic root of 665005805 is about 872.8544133133.

The spelling of 665005805 in words is "six hundred sixty-five million, five thousand, eight hundred five".