665005806 has 12 divisors (see below), whose sum is σ = 1440845952. Its totient is φ = 221668596.

The previous prime is 665005799. The next prime is 665005819. The reversal of 665005806 is 608500566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18472366 + ... + 18472401.

It is an arithmetic number, because the mean of its divisors is an integer number (120070496).

Almost surely, 2^665005806 is an apocalyptic number.

665005806 is an abundant number, since it is smaller than the sum of its proper divisors (775840146).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665005806 is a wasteful number, since it uses less digits than its factorization.

665005806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36944775 (or 36944772 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 665005806 is about 25787.7064897210. The cubic root of 665005806 is about 872.8544137508.

The spelling of 665005806 in words is "six hundred sixty-five million, five thousand, eight hundred six".