665023566 has 16 divisors (see below), whose sum is σ = 1331931600. Its totient is φ = 221360448.

The previous prime is 665023553. The next prime is 665023571. The reversal of 665023566 is 665320566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73911 + ... + 82418.

It is an arithmetic number, because the mean of its divisors is an integer number (83245725).

Almost surely, 2^665023566 is an apocalyptic number.

665023566 is an abundant number, since it is smaller than the sum of its proper divisors (666908034).

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

665023566 is a wasteful number, since it uses less digits than its factorization.

665023566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157043.

The product of its (nonzero) digits is 194400, while the sum is 39.

The square root of 665023566 is about 25788.0508375488. The cubic root of 665023566 is about 872.8621839869.

The spelling of 665023566 in words is "six hundred sixty-five million, twenty-three thousand, five hundred sixty-six".