665698 has 8 divisors (see below), whose sum is σ = 1089360. Its totient is φ = 302580.

The previous prime is 665677. The next prime is 665713. The reversal of 665698 is 896566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 665698.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15108 + ... + 15151.

It is an arithmetic number, because the mean of its divisors is an integer number (136170).

2⁶⁶⁵⁶⁹⁸ is an apocalyptic number.

665698 is a deficient number, since it is larger than the sum of its proper divisors (423662).

665698 is a wasteful number, since it uses less digits than its factorization.

665698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30272.

The product of its digits is 77760, while the sum is 40.

The square root of 665698 is about 815.9031805306. The cubic root of 665698 is about 87.3157155509.

The spelling of 665698 in words is "six hundred sixty-five thousand, six hundred ninety-eight".